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Post by djloone on Jun 23, 2016 14:58:14 GMT
Get in there..good man..up and running in no time...make sure she,s running sweet(ish) then enjoy m8..you could find yourself chasing your tail looking for that "optimum" setting..dont let tweaking get in the way of riding too much (says me that wont take mine out coz the rds wet..mary lol) LOON-E
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Post by vespasco on Jun 23, 2016 17:23:28 GMT
It did sound a little odd to me but that may just be the venturi. .. or because I was listening on my phone... Or because you were outside a farm ... I can't be sure You'll know what sounds different and soon work it out but sort it out if you think it's going to be annoying. Good to see you up and running. I knew it wouldn't take you long.
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Post by sime66 on Jun 24, 2016 6:02:07 GMT
Ich hatte heute morgen eine gute fahrt , ist alles gut , ich habe nur ein paar anpassungen machen, aber das seltsame geräusch fixiert .
J'ai eu une bonne course ce matin, tout va bien , je viens de faire quelques ajustements , mais le bruit étrange est fixe.
Ho avuto un buon giro di questa mattina , tutto va bene , non mi resta che fare qualche aggiustamento , ma lo strano rumore è fisso.
I had a good ride this morning, all is well, I just have to make a few adjustments, but the strange noise is fixed; it was only the flywheel, where I’d bashed it trying to get the piston off. When I’ve got the spare wheel back on I reckon it will sound the same as before, so that one’s sorted. I have a few sound and video recordings, but nothing exciting, and I’ll look at them later and add anything in if it’s interesting or relevant. Before that I’ve got to go and sort out my passport and visa this morning, and I expect there’ll be quite a queue…… Incidentally my CHT gauge is definitely playing up; it said –22°C this morning, and didn’t record over 98°C; maybe that was a factor in the seize; it certainly wasn’t telling me I was about to melt – a cautionary tale for anyone thinking about CHT gauges as insurance against seizing. Having said that, I don’t feel very happy without it now I’ve got used to having it, so will sort soon as poss, and before changing jetting. Riding gently on my usual short route, I just got to 7200rpm this morning - No WOT; just listening and feeling. Then I went round the lane to turn my idle down and sort the noise out (bugger the neighbours – Cornish xenophobes the lot of ‘em), then I tried starting hot and starting after five minutes; it’s all good. Tiny bit of an initial blip in rev-idle-rev, but I haven’t touched the pilot or mix yet; I might just leave it for a day or two – it’s a rugby morning tomorrow anyway, I’m getting a feel for down under again……………
Anybody want to buy 1½ scoots………
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Post by henri on Jun 24, 2016 6:18:16 GMT
damm ,must admit had stopped reading this thread as the pages of dyno/rev stuff was hurting my eyes .so didnt realise you'd had a ouchy .will have to go back n read it again now n catch up .sorry to hear of ya troubles n woes but seems like its sorted quick/smart .dont sell ,ship, theres a good scoot scene in NZ .H
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Post by sime66 on Jun 24, 2016 6:22:16 GMT
Self-inflicted injury last Saturday, soon sorted, back to normal. Yes there is much more of a scootering scene in NZ now, than there was 20 years ago; maybe I'll start an export/import business - DAMN weak pound now!
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Post by pxguru on Jun 24, 2016 14:23:36 GMT
Does it feel like it pulls better in 4th?
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Post by henri on Jun 25, 2016 8:44:54 GMT
damm, take me eye off the ball for a second an you chaps go an have a right party without me ,could of felt hurt/left out but was my fault. good to see it didnt faze you much sime an ya got it sorted quickly .i concur with pxguru about piston marks an other stuff ,an piston rings are always brittle coz of material there made from .breaking one is par for the course . marks look like a "classic" 4 corner soft/heat seize to me ,a sign of lean jetting =overheating piston.marks on crown n ali on plug suggest pinking , but ive never heard any in videos .maybe retard your timing a degree or so,an inspect plug with magnifying glass in future on chops looking for ali-ball deposits .H
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Post by sime66 on Jun 25, 2016 14:01:04 GMT
Right ya bums, listen up; you might learn something. - YOU'LL LEARN SOMETHING IF YOU IGNORE THIS AND READ THE CORRECTION - 28TH JUNE; THEY'RE A THERMISTOR NOT A THERMOCOUPLE, SO THIS FIRST BIT BELOW IS WRONG (FOR US ANYWAY).These thermocouple ring type CHT gauges read lower in warmer weather; (not because warm air=rich mix=cool engine) and it’s actually quite easy to understand why, but I’m not very good at explaining things concisely, rather than going into too many words, and you lot tend to skim posts and miss the good stuff that I’ve buried in the waffle, so do us a favour and have a decent read if you feel inclined to comment, eh. Thermocouple sensors work with the voltage generated by two dissimilar metals being heated; there are two junctions: 1) The ‘Hot’ junction is for us the cylinder head sensor. 2) The ‘Cold’ junction is either where the dissimilar metals connect to an extension wire, or where they connect into the gauge. (The extension wire isn’t dissimilar metals on a cheap model). Something like this:
What our cheap CHT gauges read is NOT CHT temp, but actually the difference in the temperature of these two junctions (actually just a Volt meter); they are calibrated at a set ‘Cold’ junction temp where they will be accurate, but my ‘Cold’ junction temp has varied by at least 25°C.
If the ‘Cold’ Junction is warmer by 25°C, ie in the Summer, then the difference between the two junctions is 25°C less, and the reading will be 25°C less; this explains what I first said - These thermocouple ring type CHT gauges read lower in warmer weather. (It might not be a linear error, but hopefully you take the point).
You can get more expensive ‘Cold junction compensation’ gauges, but that’s not relevant, what is relevant is that when I was experiencing:
a) Progression temps failing to reach sensible numbers in warm early Summer, despite downjetting the Pilot and leaning the Mix. b) Eventually seizing a ‘very lean’ engine when my CHT was saying I was fine.
My CHT was reading low because of warm ambient temp – the temp of the ‘Cold’ Junction was warmer, so CHT reading was lower. My CHT is reading negative when I go to take it from under it’s cover, because the ‘Hot’ junction (in the shade under the sidepanel), is colder than the ‘Cold’ junction (which might well be in the sun, or heating up under the black cover, which is warmed by the sun – I’m not sure if my ‘Cold junction is at the gauge or the extension lead junction).
I started my jetting with ambient temp sometimes -2°C, and I’ve recently been continuing the fine tweaking at over 20°C ambient, so as much as 25°C difference. As well as ambient air making a richer mix, it also reduces the CHT gauge reading, which will fail to show up going too lean, which I did, and which it did. I’ve ended up where I’m not happy that I’m only getting 130°C, so downjetting and pushing harder, when I’m potentially already 150°C and more.
Add in the loose plug, and possibly lower readings for that; then combined, a problem was inevitable.
I’m still investigating this; which I started looking into because of the dodgy readings I’m still getting with my CHT gauge after I’ve put it all back together, but I think I’m on to something with this, and I’ll continue looking into it whether you rabble take it up or brush it off.
I know CHT gauges don’t replace listening or feeling, and certainly not plug chops, and they will still show a spike that will need investigating, but I think what I’ve been seeing is a gradual increase in under-registering true CHT temp as ambient temp has increased – because my ‘Cold’ junction temp has increased. Although I felt a bit lost without it when I set off again on Thursday morning, (but now I think I'm beginning to understand why it was dodgy), I thInk it warrants less importance than before as far as actual accurate temperature goes, although still good for noticing differences.
Here’s a few snippets, as I say I’m still reading around the subject, but I think it’s relevant and important to my recent experiences of seize and dodgy CHT readings:
In answer to your question about pulling better in 4th, pxguru; I don’t know yet – it feels strong and smooth, still accelerating well and no flat spots, but I have not pushed it too far in any gear really; I’d like to be sure it’s all back together properly first. I have read back what you wrote before when I was preoccupied with sorting my barrel and piston, and I understand why you have suggested the change – “opening the transfers later loses a bit less out the exhaust port(s) when at lower rpm.” I’ll be having another quick ride in the morning, a bit longer, a few hills and a bit of dual carriageway if all is still well; I’ll try to get some speeds/revs/temps, but I am not rushing to push it until I’m happy, or stopping to fiddle unless I have to, or downjetting until I have the time to think and do it properly, which includes a better understanding of what went wrong. I also still have a list of snags and unfinished jobs that need sorting, and after a short ride tomorrow, those are what I want to get done first; I’ve got half a dozen unfinished job boxes in my front room again and I’ve had enough of the place looking like a shed all the time – that’s my immediate priority. If I’m running nicely now, there’s no rush, for me, getting the jetting fine-tweaked – I’m a bit worn-down with it at the moment.
H, you did miss the fun, but I agree the dyno/rev stuff did go on a bit (I think it’s interesting, but I’d had enough of it too in the end). Anyway, much of yours is history now; it was all reusable; I’m sure that top ring was more brittle than the survivor, but it isn’t important – I taped the rings to protect them a bit during reinstallation of gudgeon pin, which was really tight. This forum enabled me to sort it quickly – so much fuss was made of my seize before with new piston and rings and running in (not on here, and which I see now wasn’t necessary) – I’ve kept that other old piston from a few years back, and it’s in better condition than the one I just put back in, so I’ll clean it up for a spare now. I also just reused one of the rings from that seize to replace the broken one. It was the barrel that I was worried about when she blew; there’s a lot of time and money in that, but it all seems fine again now.
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Post by henri on Jun 25, 2016 17:02:10 GMT
interesting read on the cht's ,made sense to me , so it seems to be worthwhile you need a high-end self compensating gauge ,or a thermometer an calculator n maths lesson before riding . H
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Post by sime66 on Jun 25, 2016 17:55:22 GMT
· I think it’s still worthwhile as long as you are aware of the limitations and what it’s actually telling you, which I am gradually realising. · It’s certainly still worthwhile as a monitor to show any sudden rise for specific problem that needs attention quickly. · It was only ever a ‘lazy’ way of setting up carb jetting, but I’ve found it useful up to now, but if the above proves to be correct after investigation, it adds another variable into the equation, which would really mean that CHT readings can only be compared at same ambient temps; ie not over a nine-month, three-season period. More importantly: · I think it re-emphasises the importance of plug chops over different throttle positions for proper carb set-up (not solely CHT readings, which wasn't intended, but is easy to end up doing). · It maybe shows that these ‘budget’ CHT gauges might have limitations, which mean they don’t necessarily meet all needs, ie if you want to be near the limit of optimum carburation. (which I'm not actually sure I do now! ) I found TrailTech in USA very helpful (compared to TrailTech in UK, who are basically just a stockist/trader), so I might see if USA want to comment or advise. Price was a factor in deciding whether or not to go for CHT; there’s still some value, but whether the correct decision is to spend more (which I wouldn't have), or be aware of the limitations and get used to it (which I am), or write them of as not worth it (which I think is too simplistic), I still don’t know. It’s still telling me something; at the moment I’m going to factor in either the ambient temp or the temp the gauge displays when I start the engine. For now I'm just going to think of it as being about 20°C low and see how that compares with the plug. Initially I had a hunch that a low battery in the gauge might be the cause (that it compared voltages), but when I came across this it seemed to explain it well, but I’m still not certain it’s the correct explanation; I’ll see what TrailTech says, and carry on seeing what I can find elsewhere, AND recheck my installation and connections; it's on my never-ending list of little jobs that never seems to get any smaller no matter how many things I tick off it….....
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Post by pxguru on Jun 26, 2016 3:08:57 GMT
A few points come to mind on my early morning read. I for one always thought they were a bit of a guide and +/- 10%, at best. If they now change significantly with the weather, it is even more of a worry. They are not that far out really but what you are saying is even worse than that, in that when you really need them cruising along on a hot sunny day, with warm air cooling your engine. It is actually way worse than you think Mine always seems to be reading about the right ambient before I start up, not exact but within a few degrees. I think worth while testing the calibration so you know how much to add or subtract from your own calibration temperature (normally 20degC apparently). Am I safe to assume that however many degrees the ambient is over the calibration temperature is the amount that should be added to each reading to get the right temperature, or is it not linear? Factoring in that your engine runs hotter in the Summer due to warmer cooling air but cooler due to richer jetting is quite a challenge setting up at all. Lucky we have the trusty 'seat of your pants', 'a pair of ears for the pinking noise' and ever reliable 'plug chop' to keep safe
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Post by sime66 on Jun 26, 2016 3:39:43 GMT
I'll see what more I can find out during the week, but I think there's something in it. I also still suspect there's something wrong with my CHT readings, somewhere between sensor and gauge; however I spin it, can't really explain 22°C difference between my 'Hot' and 'Cold' junction to explain why my gauge said -22°C when I went to use it the other day; I think that's stretching the theory, whatever the location of the 'Cold' junction. I wouldn't say it's safe to assume any correction method yet, but to be aware of it. You've said maybe +/- 10%; that's not so different from what I'm saying, but it still means 150°C might really be 165°C. Too early to go into it further; I'll have a nose round and ask some questions in the week.
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Post by sime66 on Jun 26, 2016 7:06:19 GMT
Si 26/26 (drilled to 2mm), Polini vortex, RamAir filter, and.... 48/160 138 – 135 - 132 BE3 – BE3+1 – BE3+2 AC160 – AC170 04(Obstr) – 04 – ?
Weather conditions: Precip: Cloud (65%), Dry Pressure: 1021mb Temp: 13ºC Wind: WNW – 10-25kph
^^That doesn’t seem important now, but sometimes it helps when reading back to know the conditions I was talking about.
There is something wrong with my CHT sensor/gauge, other than the new theory above, but that doesn’t mean that the new theory is wrong; just not the full explanation for my current conundrum. How much of this is a contributing factor in the seize is unknown, but some reliable temp readout now is desirable, if not actually crucial, and I ain’t got one. My CHT gauge said –23ºC when I unwrapped my baby this morning; that’s just wrong (for the third time running too), not out-a-bit, and a bad connection normally just gives a ‘---‘ reading, not a wrong one. Maybe it is the battery; I have had a bit of a hunch that buying UK stock might well mean that the unit is older stock than buying from USA, so part of its five-year battery life might well have been between leaving factory, freight to UK, and sitting on a shelf. This non-replaceable battery combined with new info about Summer low readings makes me less inclined to go for another TrailTech if it is the battery. Anyway, that all needs investigating and fixing, but does leave me without reliable numbers for the time being, which makes me reluctant to thrash it or downjet it drastically either. I do think it could do with being leaner, and there’s proper ways I can safely do that as we all know, though I’m happy enough with it as it is for now. All gears are good enough to feel safe (temp-wise), but not great enough to give much of a thrill. With a few hills and a short dual carriageway run, I only got 6760rpm and 103ºC. I was using less 3rd, to get more of a feel for 4th and to keep the revs sensible while I’m still checking that all’s well with the rebuilt top-end, (although I know the lower-revs 4th gives me higher temps), so the 6760rpm is OK (was 7200rpm on second run after seize); I have not done an MD-type 3rd to see how high it’ll go, nor do I intend to for now. I reckon 103 can be thought of as 103+23(gauge error*)=126ºC, or maybe 103+13(ambient)=116ºC; either of which might be closer to correct, or still boƖƖox; I’ll look at my plug a little later so as not to annoy the neighbours too early; I expect it to look pretty rich. That’s all I’ve got to offer for now really; with this CHT problem ongoing, limited time to mess about, neglect of other things I should be doing, and general arse-ache with all the fannying about, I reckon I’ll just be happy to have it back reliable enough that I can go and and jump on it when I need it without worrying about jetting, temps, seizes etc. for a bit – at least until my to-do list is done and my flat’s tidy again, and my enthusiasm returns. I wanna be out playing now…………
*Quick Edit: Gauge error wasn't 23, it was -23(gauge)+13(ambient)=36, making 103+36=139ºC, but in any case guessing the error makes the readings pretty useless for now.
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Post by henri on Jun 26, 2016 7:42:58 GMT
-temps like that are just not right ,even in winter with wind-chill factors factored in it shouldnt read like that .to go back a bit ,from my read of the above an ancient knowledge of thermocouples ,the discrepancy should be of a linear type .as in if its out by 20 cold will still be out by 20 hot,so a quick bit of mental maths will compensate .but i think sime youve got a rogue gauge/problem going on . H
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Post by sime66 on Jun 26, 2016 8:09:59 GMT
There are two different issues here: 1) I have no doubt my gauge is wrong now; I have said so above. It is not out by 20°C though, this morning it was reading –23°C when ambient was 13°C; that’s 36°C (which might make my 103°C this morning more like 139°C), but I don’t think that’s accurate either – relying on this gauge is no longer viable, but that it was reading low when I seized is still probable. For curiosity, I should be able to check my films to see what it said at engine start-up last Saturday, the morning of the seize, too; I think I would have noticed if this wildly low starting temp problem existed then; I'll put finding that out on my to-do list of wake-up jobs. 2) There is still the matter of establishing the amount by which we can take the Summer CHT readings on a correctly functioning gauge of this type to be out; and for that I intend to email TrailTech USA, and I’ll post their reply; I think they will reply to me, they were helpful before, and it’ll be interesting to see what they say, starting by whether or not they acknowledge the creeping error with increasing ambient temp, then maybe establishing some guidance to it. My faulty gauge now, does not mean that this ambient temp problem doesn't exist as well; I think it is a problem, but haven't pinned it down to specifics yet. Maybe I’ll also revise the physics of thermocouples on an idle evening, or for a wake-up half-hour sometime too, but not this morning; the sun’s out…
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Post by pxguru on Jun 26, 2016 9:48:33 GMT
I am expecting that as it will now ride better overall the rough jetting in will be quicker to do. Forget about the CHT for a while and get it running reasonably well the old way.
1. Reduce the main jet until it revs out clean to the highest rpm and the plug still looks coloured ok. 2. Increase the size of the pilot jet until the progression (1/8th to 1/4 throttle) splutters, then reduce it until it doesn't splutter at all. 3. Re-check the main jet after changing the pilot jet and adjust as necessary.
I think that before you didn't need the AC170 or BE3+2 and this was putting in too much air and why you needed to block the slide. If you still need to fiddle with the atomiser this will become apparent once the main jet and progression are giving a good colour. Just watching the CHT and not noticing all the other signs might be why it didnt go quite to plan. I find with mine that the CHT is best for fine tuning the pilot and atomiser once the MJ is set.
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Post by sime66 on Jun 27, 2016 16:03:42 GMT
Thanks pxguru, Certainly less emphasis on CHT in future; I’ve learnt their limitations now, though I will get to the bottom of the problem I have with mine because I would still prefer to have one. It's running pretty nicely, and there is room for going leaner; the plug is pretty rich, so I’ll downjet and get my revs up (in the region 8,500 & possibly 7,500rpm I imagine?) and keep checking the plug as I reduce the Main, then move on to Pilot, checking plug at Progression too, and then recheck Main. It’s interesting to notice now that there is no low-revs dip on acceleration, at the moment anyway; maybe that’ll change when I start giving it some beans again; that’s what the modified BE3s were for before. I can certainly forget the AC170, which was only part of that last fatal triple-change actually, and I unplugged the slide air several changes back too, not recently. I am withholding judgement on whether the jetting before my last triple-whammy was so far out though; it felt really good as it was and I would have happily left it there; the temps were fine*, the performance was fine - for me; great on hills and very nippy and splendid in 3rd, and OK top speed at touching 105-110kph; though not as high as it had been before. I do agree that 4th was a bit shabby, but hopefully that’s been addressed with the transfer/exhaust timing/squish change. I’ve also checked the starting CHT temps for those runs before the seize, and on the morning of the seize, and this main CHT problem didn’t exist then (though the seasonal creep might have been an issue* – I haven’t had time to email TrailTech today); I don’t know why I’m getting –23°C now; I’ve checked it all out over the weekend – maybe the battery. I could test it by immersing in freezing and boiling water, but it doesn’t seem worth it; it’s just plain broken – and once USA have unwittingly confirmed that it’s buggered, I’ll get a replacement under warranty from UK as it isn’t a year old. I’m not rushing the rejetting anyway, or changing just for peak performance, but will do so for getting a decent range of plugs, this time I’ll stop when I’m satisfied, which I suspect will be before you would be, but I don’t want or need to be so close to self-destruction again, and I’m not convinced that 42/160, 135, BE3+2, and unplugged #4 slide wasn’t pretty close before either. (I’m on 48/160, 132, BE3 and unplugged #4 now for my next run out, and I’ll be more careful without the CHT now, but noting revs and plug as I make any changes). That’ll do for now; I’m glad to have it back in one piece, and a few trouble-free runs under my belt since then, and thanks again for helping me get that sorted quickly and simply; I’ll update when there’s anything interesting happening.
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Post by pxguru on Jun 28, 2016 5:52:02 GMT
Was just a little hi-cup in your learning curve. It didn't cost you anything so much and the performance seems un-affected. A lucky escape. It isn't always that way. Now you know how easy it happens, you're only ever two main jets away from a heat seize but any richer than that and it drinks loads, won't pull 4th and goes c**p. They are what they are, like a highly emotional Italian mistress As you lean out the MJ, there is a little more compression now so keep your ears open for the little tinkling noise when at higher revs. That's the noise that puts the marks on your piston crown. Amplify that to a lot of marks and it gets hot enough to melt through. If you do hear the noise you might need a bit less timing. You're at 20 degrees advance now, which should be fine but keep your ears open. My Polossi is 21 degrees advance with much more compression and it's fine (at the moment). More timing advance, is more torque, so another rock and a hard place. The majority of pinking issues are jetting though. Ease the MJ down like one jet a week. With the BE3 and AC160 I expect it could get down to 130 or 132 to get a digestive colour on the tip. Remember with the 2mm carb drilling the MJ is much richer than without. The most important thing the pilot jet does is progression. Need to keep that rich enough to stop the closing throttle seize but weak enough as not to drink fuel like you have a leak. Interesting that there is no flat spot this time.
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Post by sime66 on Jun 28, 2016 20:09:43 GMT
A couple of quick things to keep in mind or clarify; just jottings really that I started this morning before I got distracted: I don’t see the need to make any big changes to how it was before; I was very happy with it. – That includes any unforeseen consequential tweaks from reducing my packer height; I do not want to be continually tweaking this and it was close to done before, so I’ll be leaving my timing alone unless necessary. Good enough has got to be good enough, before I go round the bend! My timing is currently at 19°. By less timing* do you mean less time BTDC (fewer degrees - retard), or more degrees – advance? 20° would give me more torque? At what cost? (This, I could find out for myself; just jotting notes down here). Henri mentioned maybe retard** a degree; my understanding is that retard is later is fewer degrees BTDC; maybe you chaps can clarify your method of describing timing (is less timing* less time ie retard** ie less than 19° for me?). If we’re saying less than 19° might reduce chances of pinking if I’m jetted lean, but will also reduce my torque, then I’ll keep my jetting a little less-lean and keep my timing where it is for the torque. If you thought mine was 20°, then maybe my 19° is OK for now, or maybe that 20° might increase my torque, but increase my risk of pinking; I will read up on this, but I want to post this one, and get it off my desktop, and haven’t had time this evening. My Vortex should need increased jetting; I was expecting to need a considerably smaller MJ than your tourer, pxguru, but maybe with the vortex that isn’t actually the case; it isn’t my intention to compare, but I can’t help a sneaky peak now and again. I heard no pinking, though I suppose the evidence on cylinder crown and plug suggests otherwise, but it does also suggest that I won’t hear it – did I mention I’m deaf in one ear? I can’t be doing with temperamental birds; I much prefer a down-to-Earth, beer swilling Northern lass, or an Antipodean big-but beauty! I may also exchange spending my free time on all this endless theory to see if I can get my blood/vodka mix right instead; it’s much easier to understand and I’ll get more sleep, (but I can’t ride then!) STOP PRESS! I have exchanged several interesting emails with TrailTech USA this evening, and I’m as impressed with them again as I was last time. Their TTO CHT Sensor (like mine) is not a cheap and cheerful Thermocouple, it is a Thermistor (look it up if you’re interested – I’ll edit my previous Wild Allegations later); · It is not affected by ambient temp at all, · It is not affected by a low battery at all, · There is a thermistor (thermally sensitive resistor) at the CHT ring, this affects resistance, which is measured and displayed within the meter/gauge, · Mine’s fercked!! (the thermistor that is). TrailTech USA is sending me a free replacement under warranty (even though I bought it from an Ebay UK dealer), by UPS today – bless ‘em! The chap explained how it works, identified my problem, and offered to send a replacement all within the space of a few hours. God Bless America!
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Post by henri on Jun 29, 2016 6:16:36 GMT
until trump gets in , but that is excellent service from our colonial boys . the timing question , i thought you were running 20-21 btdc thats why i suggested retarding ,but 19 is stock an were a dr is suppose to be .pxguru's comments ,more advance=more torque, but closer to the pinking zone an slightly hotter running .more retarded = less power but safer ,as he said "rock/hard place .an to be clear ,advance=more deg's btdc ,retarded less btdc . H
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Post by sime66 on Jun 29, 2016 7:39:00 GMT
You don't wanna start me off on Trump!! Did you see the obnoxious goading Farage gave in Europe yesterday; someone wants to shut that c--t up; he's demented and dangerous!! Anyway, this isn't he place for all that, though it bothers me a great deal.
I had a little look this morning; Koso CHT is a thermistor, so I imagine SIP is too. I have no idea what that other lot were banging on about in those posts I found; all sorted now anyway. I'll be taking the old one apart; someone on Not-so Modern Vespa has made their own CHT ring from a $2 thermistor, and there's loads on Ebay; I looked early this morning then went back to bed for an hour. I knew advance is more degrees BTDC, retard is fewer; the 'less timing' was less clear. I'll have a proper read about how timing affects stuff sometime soon; I've realised you chaps have got a grip on something that I haven't picked up on properly yet, or I've understood it once when I've read it before, but the old brain just doesn't hold on to as much stuff first time round as it used to; a bit of new info overload going on with all this for me.
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Post by vespasco on Jun 29, 2016 17:12:28 GMT
...... my understanding is that retard is later is fewer degrees BTDC...... yes you're right Interesting about the CHT too. I started wondering if the 'cold junction' was relevant to our CHT gauges when I read up on your links but couldn't quite convince myself enough, until now. Thanks for the info. Timing - I try to set mine as advanced as possible - without it pinking
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Post by sime66 on Jun 29, 2016 19:33:38 GMT
….and advance (more degrees BTDC) is more torque, but hotter and more chance of pinking. – Got it. You may well like to have yours set as advanced as possible without pinking; I’ll just leave mine alone if it isn’t giving me a problem, ‘cos I’ve had enough fannying about for now. That’s that one sorted and put to bed then. The CHT thermocouple Red Herring is also identified and now averted; I didn’t just jump on one post; I cross checked and collected several before I posted mine, but we can forget about thermocouples now anyway; it’s thermistors and varying resistance. My CHT (the thermistor) sensor is broken, and TrailTech are sending me a new one under warranty, so I’ll get that fixed sharpish, and even though I must depend on it less, I’ll be happier to have it working again. I’ve also got a cunning plan to experiment with making thermistor/sensors for a few pence instead of the nearly £30 for a replacement one from TrailTech, and a 12v option for the gauge when the battery goes on mine; if it all turns out to be nonsense I’ll only have wasted a few quid and a couple of hours. I’m thinking I can get rid of the (loose/fragile) ring problem too by tapping it into the head, like you experimented with vespasco; exactly how is something I’m still pondering, but here’s a little sketch of an idea I’m working on:
…that might be too fragile, or not conduct heat quickly enough; I’ve got lots of thicknesses of copper sheet, so can have a play with different options, even making plug rings if I need to, a chap on not-so-Modern Vespa did this (below), but he’s used the wrong thermistor, and I reckon I can make a better ring than that too:
There’s two cheap 12v LED gauges on BangGood.com (your cheap and cheerful site, H; remember?) I’ve got a 60mmx30mmx30mm Celsius one from BangGood EU warehouse for £5.15:
eu.banggood.com/Wholesale-Warehouse-12V-40110C-Auto-LED-Digital-Thermometer-Meter-Probe-wp-Eu-994934.html#
www.banggood.com/F-Fahrenheit-Digital-Thermometer-High-Temperature-Meter-NTC-100K3950-Sensor-1-Meter-p-1031327.html
…and these are the 100k NTC/3950 (-50-300C) thermistors, five for £1.76:
www.ebay.co.uk/itm/191885437601?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
You can get them quicker from UK if you pay more, but I’m in no hurry; it’s just a little project to think about, for times when I haven't got much on, which isn't now anyway.
This is the sort of tubing, or maybe refrigeration tubing; I know the more expensive thermistors in sleeves come in ø3x20MM, so 12” costs £1.40; it might be too fragile and I might end up using thin copper sheet and making a sleeve; it has to conduct the heat well, and protect the bulb of the thermistor:
maccmodels.co.uk/materials-metal/copper-sections/copper-tubes/metric-copper-tube/3mm-dia-copper-tube-0-45mm-wall-12-length.html
This is the sort of thing I think is in the TrailTech sensor (I’ll dismantle my broken one to see if I can actually read the thermistor part no. inside):
I do realise it might be a waste of (only a little) time and money, but it might also be bleedin’ marvellous – Who Dares Wins, Rodders!
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Post by pxguru on Jun 30, 2016 3:28:59 GMT
Good news our gauges are not so terrible. They still read hotter in the Summer though. I think mostly due to the hotter air. A few weeks ago (when we thought Summer was coming) I was riding back from Brighton at a steady 70 mph cruise and noticed my temp up at 310F (normally this would be 290F) tried to slow down and it just got hotter, up to near 330F. Just sped up again and rode the home at 310F. Nothing happened. I think inside the engine is hotter but not as much of an increase. Interesting to make your own sensors. Good chance they will work but for how long?
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Post by sime66 on Jun 30, 2016 4:07:48 GMT
Warmer cooling air in Summer temps is another matter again, but the balance between that and the warm air also meaning richer, cooler combustion, is something I’ve yet to weight up in an engine that isn’t still being tweaked. Also there’s this (generally accepted, but we know how most like to accept scooter-myth and pass it on as fact without checking) question of how much more of a problem is caused by using air from under the sidepanel, rather than from under the seat as intended. I wonder if these vented LML 4-stroke type panels would be a neat way to get some fresher air in there? I know you like to look standard, but this is quite discreet, though bloomin’ expensive at UK£80, and rising now we’ve cut-loose………………… (I see you’re practicing mph and F with gay abandon now we’ve elected to return to the dark ages).I also wonder if I can make a long-lasting, accurate thermistor sensor, but I’ll have a go; I can knock up a few in an evening for a few old-Bob or maybe a Florrin, and no harm done either way. This is the panel I mean: www.ebay.co.uk/itm/FA-ITALIA-NEW-PX-SIDE-PANEL-ENGINE-SIDE-RHS-FOR-VESPA-PX-125-LML-4-STROKE-STYLE-/322071176528?hash=item4afcf02550:g:akUAAOSwjMJXC8xIAnyway; a nice early start and dry – I’m going out to chase some bunnies round the lanes!
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Post by pxguru on Jun 30, 2016 10:07:20 GMT
A Forrin! That was an old English version of the euro. There is no chance we be using any of that anymore maybe half a dinary? I never left mph or deg F they have always been like a 'special relationship'. You can poke feet and inches though...not even accurate enough for woodwork. Forgot to respond the other day, my tourer is just a P200 iron barrel. Bored out to 210cc. Its been tuned a lot but still in the tourer bracket. We do have the same carb and similar inlet timing, so comparable. I would say mine will have more torque but yours revs higher and will need more jet, plus the vortex will need even more jet. Probably about the same performance overall but the difference will be like the colours, yours is black mine is white How did the 132 MJ work out?
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Post by sime66 on Jun 30, 2016 18:09:43 GMT
Hmm; I’m not really ready to answer on 132 yet….. I don’t want to be too critical of performance too early in the re-setting up, but as you specifically asked I’d say it felt noticeably less-lively now that I’ve given it a bit more of a thrashing; still good, but not as good. I wasn’t out long because I didn’t have my Petrol Ration Book with me, or Threppence for air to check my tyres, but long enough to say the revs ain’t there yet. I’m not worrying though; there’s plenty of jetting and tweaking to do before that. What I’m really tempted to do, but I think you’d advise against it, is give the last good set up (before the triple-whammy) a quick go for a direct feel comparison to rule out anything else that might be an issue (loss of compression after the clean-up? Old rings? The reduced timings? Anything else – I haven’t given it too much thought yet, but things that might be different post-apocalypse). The last known good set up, where I was very happy and should have left it alone, was 42/160, 135, BE3+2, and unplugged #4 slide; it wouldn’t hurt to bung that lot back in for a quick and careful spin and let my arse do the talking would it? It would save floundering about, and highlight it quickly if something has gone wonky. If not, I feel inclined to spend some time on the Pilot before reducing MJ any further. Re: comparison; I meant jetting rather than performance – similar volume flow rate with your cc and my revs and vortex? Did you mean like chalk and cheese, or the only difference would be the colour!?
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Post by pxguru on Jul 1, 2016 5:04:16 GMT
How is the plug looking after a WOT session? I think you don't need the BE3+2 yet. It will feel a little less lively but more torquey, as the 0.2mm packer is missing now. You might have been too close the the edge before. Just work with the two variables for now, MJ and pilot. It will end up better. The MJ was just too big before and that on the SI carbs that makes the pilot over rich. If you can keep to the unblocked slide, AC160 and BE3 is will be much more durable once the Summer slides back in to Winter. If the MJ is giving digestive colour on the plug tip already then that's done. Then work on the progression. Could be over the worst of the tinkering in an afternoon. There is nothing wrong with the mechanicals. Rings might take a few hundred miles the run-in before the seal fully. It may not be as quick as before but it will be honest this time. It is a touring set up after all. If you want a fast one we can do that with old faithful Running crisp at low throttle and pulling 4th from roll on, is the key to riding comfort. I meant with the comparison is that they will jet in similar, perform similar but in terms of riding feel you can't beat cc. So they will be quite different to ride overall. Still not easy to explain but would be clearer to see if both were touring with a pillion.
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Post by sime66 on Jul 1, 2016 8:40:31 GMT
Lie in this morning - sorry about that; to business: What WOT? I think the bunnies were laughing at me - Plugs so far then: With 135 didn’t really get a WOT; I was more checking it was all back together properly and sorting snags out, but was clearly waay rich:
So I went straight to 132; which was a bit odd, and I decided to adopt the ‘ignore it and it might go away’ approach to jetting – an old technique, not really encouraged in modern-day text books. It still wasn’t really a proper WOT, only getting to 7,100rpm in 3rd; slight uphill slight headwind, and a bit sad in 4th (it was a short WOT, but it didn’t feel like WOT – felt like I should stick to 3rd, but wasn’t really getting high enough in 3rd for 4th) so I didn’t bother with dual carriageway, and it came back with plug uneven and an odd orange colour on one side. I’ve had that orange before, can’t remember the circumstances, and it was gone the next time. I’ve left 132 in for now, and will just give it a better run and a fairer chance of getting hot and showing something more definite:
I was intending to keep all this vague info to myself for now, until I’d had longer runs and more useable data on the weekend: I’m not really ready to answer you.
It did run a little hotter with 132, according to my wonky CHT; it went to 108°C max, which is up 5°C (starting from –19°C when ambient was 15°C, so I reckon add 35°C; maybe roughly 140ish. I know that’s pretty useless data, but some idea, though I think that’s higher than true anyway. I should have CHT back soon; my replacement sensor is flying over the Atlantic as we speak; maybe I’ll get to replace it over the weekend. I’ll be happier WOTting properly if I’ve got it back working; although I’m trying to get used to not relying on it, I’m still not so happy going silly without it after the seize, and I’m taking it easy really, until that’s fixed. When I do the CHT, I’ll retorque the head and have a quick look for leaks, just to be sure; there’s always a bit of muck around that CHT ring too, which I’d rather not keep seeing – maybe a relocated sensor might help (Mk1 DIY-Thermistor is pre-production still). If, as I suspect, the plug is still rich after a decent WOT on the weekend, would you think it safe to go to 130MJ before changing and resetting the Pilot then? I feel a bit cautious about doing that. Because my short 132 run felt unencouraging I didn’t make a longer, or dual carriageway run. Afterwards it ticked over at 1200rpm, but it actually cut-out in neutral when I pulled up at home, and had taken three kicks to start cold too – not had that sort of nonsense since the bad old days of aggro with Old Faithful not being jetted very well, or when rings needed doing. I need longer to get a better feel for it, and a chance to let it settle and sort some niggles; I’m not sure I’m ready to be too critical or make decisions on the couple of short runs I’ve done so far; it's been a busy week. At present top of each gear seems lower, and I seem to need my revs up more in 1st on a standing start before 2nd starts to pull on a hill, (I have a junction on a hill where I approach a give-way downhill, then do pretty much a U-turn and pull away uphill; I could do that easily in 2nd before, but now it seems to need 1st first to get the revs up), but then with the revs up it still pulls well – those things make me wonder about BE3+ and Pilot, rather than MJ, we’ve got a richer Pilot and less air at low revs at the moment; I suspect I don’t feel a low-end dip because there isn’t even really a surge before the dip now. I know you thought I might have been too near the edge before, and I’m happy to test and fiddle in my own time as long as I’m still able to ride, but I need longer to draw conclusions on the MJ alone if it is to be MJ first because to me it’s going too small now, and I can’t see past it being because of the other jetting components. Maybe I should let it be for a while and give the rings some distance first; or maybe spend a bit of time on Pilot, Mix & Idle, then Progression; or maybe go 130MJ – dunno really; not that bovvered – it’s early days; just three short rides so far and probably too rushed to do it justice…...
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Post by pxguru on Jul 1, 2016 10:55:19 GMT
If that 6 picture plug is from the 132 MJ then it says it's way too rich to me. Going to probably end up at 128 MJ by the looks of it. Sounds like the pilot is still over jetted (so that's safe for now) but get the MJ down to a digestive colour before doing anything more. There will be some room to move the pilot down without going lean at WOT.
Good that it is still way over jetted and feeling like it is. New ring will run itself in before you know it. I am trying to suggest a different way of jetting it in this time so that we really know if it needs any atomiser mods.
I would say next time out 130 MJ and see how the plug colour is if still not Digestive coloured go to 128 MJ.
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