Weather conditions: Precip: Blue sky and black clouds (50%), Hail Showers Pressure: 1007mb Temp: 3ºC Wind: NW – 4 knots
Don't really need that, except to note that it's a fair bit cooler, so maybe a bit leaner.
This info is for setting up 48/140, concentrating mainly on Idle circuit and Mix and Idle screws, but a bit of a test up the range a bit too.
I think this is much better than the 50/140; I have the screws at sensible turns with predictable changes when adjusted, my Idle-Rev-Idle is good, my slow/low revs running is excellent, my Progression speed temp is possibly low, my acceleration is splendid, and maybe my temps at higher speeds are a bit high. Here's the detail:
I started at Mix and Idle 1½ each to warm up. When warm, I turned the Idle to 2¼ to slow it at tick-over. When I turned the Mix to 4, the Idle needed to be at 3¼ to idle OK. The revs picked up as I wound the mix in to 2. I then did a bit of adjustment of both screws to get a low idle and no flat spots in revving; I went through various adjustments, keeping track as best I could and ended up with Mix=2, Idle=1¾, which is when I did this film:
Idle-Rev-Idle, 48/140:
(I could possibly turn the Mix in more and the Idle out a bit, but I was being cautious – tweaks later maybe**?)
From that I went to slow running, which was good and smooth at all low revs/speeds. I then did two or three runs up the lane at Progression speed, but that was quite cool – 89ºC (not too bothered about that; better than too hot, and I'll spend more time on that later anyway; **maybe less on Mix screw, maybe a /160 – too soon to say). I then did a couple of maximum acceleration that I can safely do in the lane, and that was excellent, back to feeling like the Beast, but possibly a bit too hot too quickly (103ºC). Maybe my MJ will need to be bigger again – too soon to say; it's 145MJ now though.
All in all, I think this is much closer to where it should be; the 48 feels right. Some a fine balance with the Progression temp being low and the MJ temp being high will be needed, but I'll have a better idea of temps after a proper speed/temp-range ride, which won't be until Saturday, with maybe a Progression plug chop with a new plug on Sunday if that goes OK. I'm not around tomorrow, so plenty of time to assess and get feedback before the weekend, but I liked this test this morning; it feels close.
Liking the sound of this! Would seem like 48 is just right after all. The progression temperature should be cooler than normal running, about 110 deg C would be better. See how it is after the MJ is set but sounds like you might need the 48/160. MJ next and a 3rd gear WOT plug chop. Get it really very hot before doing this, maybe afte a fast run.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I liked it, but always feel better about it after the nod of approval too. Do you think I should do the 3rd gear WOT plug chop before a Progression plug check this time then? Just as long as Progression temps aren't high if I do a set of varying speeds/temps run? I suppose it's OK to do that because it's rich if anything, and it can have a tweak (maybe to /160) after the MJ; I'm just double checking you mean that because it's not what I was intending. I'll be very pleased if my MJ comes out somewhere near where it is and I've got my performance back and the temps back under control now. I'm sort of thinking that, as the weather is a fair bit colder now, by about 10ºC since before Christmas, this will all need a bit of a check later in the Summer too – just above freezing isn't really an average temp for the year's riding, but I suppose if it's OK when it's so cold, it'll be safer when the weather is warmer anyway.
I would do the MJ next then go back to the pilot before moving onto the main atomiser. Will probably need the 48/160 but see how it goes. Will need a re-tweak in the Spring and that should do it for all seasons.
One of many tests to confirm the pilot is big enough is to ride at high rpm. Like WOT in 3rd, then only shut the throttle fully and see how the revs decay. Should be no popping or misfire.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Because, for the first time in ages, it wasn't raining, and because there was no film of scooter running when I did 'It's alive' film, I took the opportunity to do a quick bit of film of myself up and down the lane this morning, and I thought it might be useful to hear the engine without the helmet on for me, and maybe for anyone with a trained ear for such things. I've left the film uncut because you can hear the scooter for longer than you can see it. I can't really go full throttle up this lane now; if I leave it long in 3rd I only get a short burst of 4th before I have to brake for the U-turn or the S-bend; it's a dodgy mix of muddy and frosty too, but it gives a bit of an idea of how she's running. I noticed the throttling off engine noise, which might be indicative of something to tweak but hasn't bothered me before, and I think I can wind my Idle out a bit more too, and probably tweak the Mix in slightly. It also still did not get very hot, so I'm thinking that the /160 is likely, but that can wait until I've had a play with MJ. MJ plug chops might be a while away because I've had to put the muffs on this morning, so will wait until it warms up enough to chop without them. I thought I might do without them altogether this Winter, but it's turned very cold in the last few days and there was a thick frost first thing. - Snowing on Dartmoor yesterday too. I'll probably just have a ride tomorow with muffs on and get some proper numbers for temps at different speeds/revs.
Anyway, a bit of film; might be useful, might be entertaining, or might be neither – it's done now either way......................
jesus , shorts in this weather , your nuts . an in this weather its not worth trying to dial it exactly in ,soon as its warm again it will go boggy on ya . does sound sweet to me ,seems to accelerate clean n fast ,not sure what you mean by the off-throttle/overun noise . an also ya temps will be low as ambient temperature of the airs rock bottom at moment ,plus the chill factor of going so fast .every 10mph = 1 degree less ambient ,so if like here its hovering at zero ,doing 50mph= -5 ambient , Bbrrr . an shorts ,crazy . H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
My first impressions as well; too cold for shorts! And never really safe enough.
Looks and sounds good but I think MJ is too big and the closed throttle sounds a bit weak, can't really tell so well. You can do all the jetting by temperature if you can't be bothered with the plug chops. you will need to do them again in the Spring anyway.
I would say, progression 110 degC, 140 degC fast cruise and 5km WOT 150 degC max. When you get to these the plug will look fine.
Get the mixture screw a bit richer and see how the run down sounds. Then the MJ. Then see how the progression temperature is. if you are going for a ride anyway, take the jets with you and it will be all done by the time you get back.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Temps – 48/140 145MJ: Progression chop speed (I'm using 30kph gps in 3rd) – ± 95ºC Cruising at 70kph gps in 4th – ± 115ºC Quick WOT in 3rd to longer WOT in 4th and hold – 120ºC – (the temp didn't rise when I throttled off) 5km WOT in 4th on Dual Carriageway - 140ºC (110kph gps, 68mph = 7250rpm – I got 8000 in 3rd before)** – (the temp didn't rise when I throttled off)
pxguru, you made a couple of suggestions yesterday, neither of which I've done, as follows: --- I did not richen the mix because my progression temp is not very high, and going by temp it does not seem lean as I throttle-back; maybe I could go to 48/160 and richen the mix screw? I was going to say yesterday that I was thinking leaner not richer was needed, but decided not to raise the point yesterday before I'd checked the temps. --- I did not down jet the MJ because 140ºC seemed high enough – **I wasn't full WOT for full 5km because of fog, (I eased off when it thickened in dips a couple of times) and I'm pretty warm-enough at 110kph not to want to be much leaner, I think. But there does seem to be more guts in 3rd than 4th, though I rarely see myself doing long 4th gear WOTs anyway; sitting for ages full-throttle on a dual carriageway is not what I want to do at all. I'm also thinking that a 142 is quite a big drop from 145, so I'm wondering if I should open one of my 142s up to be between the two (an ss143and-a-bit) – I'll maybe do that after trying a 142 to see if it gets too hot with that. There's also still the question of the mixer tube to tweak that a bit too.
I don't really want to mess about in the fog anyway; I've got good performance and good temperatures. I can fiddle towards the end of next week, and the forecast for next weekend is warmer and dry, so that looks like a good time for a Saturday tweak, and maybe some MD and 0-60 numbers on Sunday. The point is now, I'm happy with it, I can use it with confidence and it's great to ride; it's not too hot, and fine-tweaking now will have to be repeated in Spring anyway, when I'll be doing proper plug chops too – it was not my intention to avoid those, just seems a bit tricky and unnecessary at the moment – it never is that I couldn't be bothered, not after a year of working on this. I always take my jets with me at the moment to make changes if there's something obvious, but I prefer to come back and think about it, or ask, where I'm not certain what is best to do for the best.
Henri, don't want to get too bogged down in ambient temp figures, because I think the point where ambient temp (cooling) vs combustion air temp (leanness) has different effects is not precise or constant for all, but I'll note that ambient temp was 4ºC warmer by my gauge this morning, and my running temps were warmer too. I still say that cold air will not necessarily mean colder running temps because it is denser, so leaner – there's a balance there, and I don't know the facts. It is interesting to notice the difference for my engine though. Example: My 140ºC WOT: - We can expect it to be warmer in Summer because ambient temp will be warmer and cooling is less efficient. We can also expect it to be cooler in Summer because warm air is less dense, so richer mix, so cooler combustion temps...................(I don't know which will have more effect on actual engine temp; I expect there's a point where it changes, and plenty of other factors, no doubt). Fog must make a difference too; warmish, wet air – the volume of air has less oxygen, and water vapour too.
Anyway, I want to finish painting my mudguard today; more on that on the other thread soon.
(Yes Mum; I had long trousers and clean underwear on)
The mixture screw won't affect the progression temperature so much. If you think that when you close the throttle from 8000 rpm there are no popping or wobbly noises, then the mixture screw is set rich enough. I thought it sounded slightly fluffy on the video but it is hard to tell. You won't see the CHT temperature increase as it takes too long to change (EGT would show it).
You should put in the 48/160. We both think it needs it. Once that is done it will cause the MJ to weaken off a little and might just be enough to get a few more degrees C at WOT.
If the temperatures all read better after that then there will be no need to fiddle again until the Spring.
68mph on GPS is ok but I would have thought it would do 70. Have you still got the ignition timing set at 18 degrees? Must seem pretty fast after the old engine
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I definitely agree the 48/160 is the next move; in fact I already nipped out changed it since posting, after thinking about it a bit this morning - ready for a quick ride later in the week when I get time. That will decide whether or not the MJ needs changing as you say. Although you'd said do MJ first this time, it seemed to me that a rich Pilot was suspect for the low temps and I had the /160 up my sleeve. It will go over 70mph; I have no doubt about that at all. I was easing off because of the conditions this morning, and it was not feeling quite as lively as it was before the carb mods either because it still needs a fine tweak as shown by temps – but I actually thought 140ºC was probably enough anyway for this test given that Pilot is rich and possibly MJ is too. There's more there, either just on a drier road and where I can see the road I'm riding into (I couldn't even see my exit off the dual carriageway this morning), or with a bit more fine down-jetting when it's clear and dry. That top speed and revs WOT is not the aspect of it that bothers me too much anyway – I know we want to prove it can do it, but that's all really; the 3rd gear acceleration and holding on in 3rd is what I really enjoy about this engine now, but feeling it go on better in 4th would be good, but I do not expect to ride it prolonged WOT in 4th as a rule. I also feel sure I could quite safely down-jet to record some pretty special figures without blowing it up! - Just to prove that point, even if I chose not to leave the jetting there afterwards. My ignition is set at 19º, and strobes pretty much there too; slightly advanced of that actually – there's the film and data on page 5, here:
This is my speed/revs table; if I get 8000 in 3rd – 90kph (which I was before the carb mods), and even 7500 in 4th - 115kph - that'll do nicely for me. I really don't want to do much more than 70mph/115kph/7500 in 4th; that wasn't intended really either. 8000 is 75mph; maybe that figure is enough to prove the point? Safely (temp and plug-wise) on the slightly lower side of that would seem to be a sensible target.
I did want you to try the 142 MJ but if you are being careful you can work up to it once the 48/160 has settled in. Should be no need for a half jet and the pilot might be enough on its own. Running optimal now should go to rich in the Spring.
7500 in 4th was the target. set up right it will make it. I remember it is set at 19 degrees now. When 3rd pulls well and 4th is flat, sometimes you can get that extra bit more pull out of the timing. I think you could safely get yours up to 20 degrees but only after the jetting is done, if needed. Getting it running right in 4th is the best indicator of how it is set up. No need to use it like that once it is done but important to get it running right for long reliable cruising.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Just a quick update with no specific speed/temp numbers - yet. I put the 48/160 in, but because of time all I did was wound in the idle ½ turn to get it ticking over nice and slow, so still Mix=2, now Idle=1¼ . I will need to do mix and idle properly, but slow idle, idle-rev-idle, and slow speed/rev running were good, so I decided it was good enough for now – I mainly wanted to have it ready to ride on the road next time I have time, without having to tweak before I go (that way I don't have to wait for daylight to get on with it - geddit?). Temps weren't noticeably much higher after the Pilot change just in the lane though, so I thought I'd give the 142mj a quick go too. With that in there is a good increase in acceleration and temp; that's just in the lane though, so whether that will be too much or not will have to wait until I get the chance to have a good run on the road – hopefully in the next few days. I will take the time to set the Pilot up properly too; should have some useful numbers for it all with 48/160 & 142 soon. If I've got decent temps with the varying speed runs like I was doing before, I'll do the 5km up the dual carriageway as well; I see now that we're thinking of 150ºC as the optimum, not the max safe limit; I was staying under it at 140ºC, thinking it was safer and expecting it to rise when I throttled-off, but now I'll aim for it, and can hang on at WOT longer until I get a satisfactory revs/speed in 4th (at least 115kmh=70mph=7500rpm – I don't think that will be a problem). If I haven't got decent temps, I'll come back and start properly with the Pilot setting up; maybe I'm trying to skip a step, but I've got my CHT gauge to warn me if I'm wrong. I also made the point that the temp didn't rise when I throttled-off because it was doing before (before the carb mods), and because I thought it might be relevant to the lean throttling-off question that was raised, and which I'm keeping an eye on. I take your point about good running in 4th being a good indicator of set up, and see why it's important to get it right. Noted; there's the possibility of adjusting the ignition timing a little too; later, maybe. - still got the atomiser to play with too. I understand it will be richer when weather warms up a bit; my point was that running temp will not automatically be warmer or cooler, just because of ambient temp – we keep talking about this, but don't seem to make a conclusion, so I'm just sticking with how I picture it until my possibly dubious theory is replaced by a more reliable one. - I know warmer air will give richer running; I'm saying that it won't automatically, necessarily give hotter running. That's it for now; I'll have some numbers in a few days.
Pxguru – read your thread; If I've got any MJs or pilots you could use quickly to keep it moving, I can post them 1st class first thing in the morning if you PM or email your address. All the Pilots on my table above, and I've got lots of loose jets above 140 and an unused BGM 140-162 set too. I've missed tonight's post, so you can probably get them just as quickly yourself, but if it helps...........?
Temps – 48/160 142MJ: Progression chop speed (I'm using 30kph gps in 3rd) – ± 90ºC Cruising at 70kph gps in 4th – ± 105ºC Quick WOT in 3rd to longer WOT in 4th and hold – 115ºC max (Didn't play with traffic on dual carriageway; little point as these numbers are too low to be worthwhile – on reflection I should have done, just for speed, but I'm back in the warm now and stuff to do).
I'm only posting out of interest really, and to refer to later, not really of interest to anyone else; I don't think anything can be read from this at such low ambient temperatures. Just two things occur that may just be worth a quick note:
1) A lower ambient temperature definitely resulted in lower cylinder temps here; even when the cold, dense air made mix leaner – that's just for interest and following on from previous discussions. 2) It also shows why it would be better to make the adjustments and tests on same the day under same conditions in one session, rather than spread-out over a few weeks; comparing the 145MJ @ 4ºC with the 142MJ @ -2ºC doesn't really give a usable result here.
I'll have to redo this one in a few days time when it warms up a bit, but it does seem likely that I'll be 142MJ or smaller – but no conclusions here. Nice ride on a dry, bright and sunny morning though...........
Message to Rum Babba: – The Postman bought me something interesting this morning, but it needs quarantine!
Very interesting that it doesn't get so hot when its so cold. Could be some useful information with the new jetting at the same ambient as before. Vespa forced air cooling is actually too good for the UK.
How is it feeling now? Noticed any issues anywhere in the rev range with this jetting?
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I'm slightly suspicious of my own results here, but wanted to note them down anyway. I will get proper readings with more comparable conditions between the two, which will be more reliable. With the down-jetting and leaner air too, I did expect hotter cylinder temps – I recall seizing in the snow before, so I've always thought very cold air would be hotter running (but with lots of unknowns and variables – I think this is more complicated than a linear graph). Things to consider: When I cracked the ice off the scoot this morning, the CHT gauge said -14ºC; I've mentioned it before that it does seem to read very low at low temps, though there were some possible reasons offered for it before. Maybe it just needs longer to get up to temp from such a low overnight temp. That's not likely though because when I redid the progression temp after doing the quick 4th WOT, it was still low, after the hotter WOT temps. [[[The heat in the cylinder is from combustion and friction, I imagine. The fuel lubricates to reduce friction, but the air/fuel mix also determines the combustion temp. The cooling is determined by the speed (which depends on revs) and temp of the cooling air across the fins (and fin/barrel material etc., but trying to keep it simple). I'm thinking that a mainly high rev low gear run (like this morning), might get much more efficient cooling than a long, hilly slog with lower revs where the engine is working harder and there is lower revs and lower speed of cooling air across fins; I's a bit of a germ of a picture that's sort of coming together, but I've got myself a bit muddled whilst trying to write it down – is there any decent reading on this; it's quite an interesting subject. - All I'm trying to say is that I think there are conditions where the temp of the cooling air and the leanness of the combustion air will have more or less effect on the cylinder temperature.]]] - I'm using those unbranded jets I got from Beedspeed, and although they measured OK, it might not be such a good test as if I was using a set of jets like the BGM ones, where I'd be comparing like-for-like with reliable graduations in size. - maybe this 145 and 142 aren't so different.
How's it feel? – very good, especially in 3rd, where I'm getting my 90kph again, which has sort of become my benchmark for 8000rpm there. I get a good surge in 4th too, as I change up and open up quickly, which is good, but it doesn't pull like it does in 3rd, or for as long before the speedo is just going up slowly.
Any issues, anywhere in the rev range? – No, none; it feels good through the range. I'm beginning to think I'm getting the jetting close to where it should be, but I need to confirm: 1) that I'm hitting the target speeds/revs in 4th. 2) that I'm getting safe temps when I'm up to speed in 4th and when I've got sensible ambient temps. I've been pondering the atomiser recently, but I know where not there yet. I'm picturing the dyno curve (Ps), and in my mind dividing it into the four rows of holes in the atomiser, and thinking that the atomiser can be used to tweak the shape of the curve (like I think vespasco did on one of the occasions in his Rally thread when he got nice numbers before blowing-up – and like that David Vizard, Weber emulsion tube video). I'm thinking that if I get OK temps when I do this run at a decent ambient temp, I might do a cheeky MD and 0-60 run on Sunday. A quick MD curve might better answer the question of how it is across the rev range, and maybe give some hints about atomiser tweaks. I'm probably wrong, too far ahead of myself, or barking up the wrong tree, but I've been absorbing info and trying to picture how it might apply to my curve, the atomiser tweaking, and now your question above.
To get a better idea of ambient temp vs cylinder temp for my engine, I'd have to leave my jetting alone (like, maybe when I have it as I want it), and then do the same set of runs at the same speeds at different temps (through the year?), and hope other conditions, like wind speed/direction, atmospheric pressure etc didn't make too much difference – there's lots of uncontrollable variables that might affect it. I don't think you can draw any reliable conclusions from just a couple of runs. I suppose this is where an indoor, constant conditions, dyno set up would be useful, without which I'll just keep on with what I'm doing and recording the results however unlikely they are – more results will give a better picture.
I'm noticing my clutch is getting pretty stiff after fast runs; I'm picturing it slipping and getting hot – could this slipping be part of the explanation why my 4th is dropping off a bit? Might I need meatier springs? I've got 16 standard springs in there at the moment. I'm not looking for extra jobs; I've got a backlog of stuff that needs doing already; I'm just thinking aloud really to see if it makes sense.
That's all a bit waffly there, but some of it might have been worth writing down............(might get a tweak in the morning)
Its a bit obvious but when its feeling good all across the rev range and throttle positions then you are very close Just need to final check the temps and plug colours in the Spring. Hardly worth jetting it any closer at the moment as it appears to be over cooling according to your CHT. If its riding fine I would just check the Progression, WOT and mid plug chops. If all are not lean then that will do until its warmer.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Going by the temps I got yesterday, and having had a quick look at the plug whilst I was doing some other jobs this morning, I can confidently say it is not in danger of being lean; in fact, it seems to still be rich. I suspect I'll try 140 (INC) at some stage (that Beedspeed unbranded 142 is suspect), but it really is good to ride at the moment with this jetting, and there's not much point fiddling when the temps are varying by 10ºC day-to-day at the moment. This is the plug – NOT A CHOP – I just put a new one in ready for some decent riding on the weekend, so took a photo of the one I took out:
i'd be happy to bimble around with that plug colour til spring has sprung an temps rise . just no long wot blasts unless 1 eyes on temp gauge .only a year ago,eh, how time flies when having fun ,an how far youve come . H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
Top work Sime..allready said this thread will become a invaluable assett to me and lots of others on here.....but they are meant for riding..get out enjoying
I have very similar jetting to yours and my temps are on average 105-115degrees city driving. At 100km/h indicated it varies quite a bit from 135degrees up to 160 depending on headwinds tail winds steepish uphills Anything over 110km/h my temps start to drop on average, especially drafting cars/trucks on the freeway light throttle overrun. It seems to hold very steady temps at 120km/h indicated 164-170degrees Celsius.
Please note these are indicated speeds. 120 indicated is only around 108km/h Gps. My climate is Qld Australia we are in the middle of summer and it's hot humid 30degrees c. High humidity
Malossi166 ported matched Serie Pro flowed reed valve crank 57mm Malossi 30mm phbh carb/reed valve manifold kit Opened intake to match Malossi manifold Ngk BR9ES Flywheel milled down to 1.6kg Sip cnc ultrastrong clutch with L reinforced springs and updated circlip readspeed unlimited cdi 3 degrees retard Sip performance left hand 22 tooth primary up gear and larger 100/90/10 rear tyre
That plug is looking very safe but mostly mid?! You need to do the three plug chops before you leave it. No need to leave it really rich as it will only get more rich, as the weather warms up. I suggest you try the 140 MJ before the plug chops.
That seat is looking cool Changes the whole look. Is it not a bit hard for touring though? And it really should have an MPH speedo.
Shame your scooter runs so well! It might not have atomiser problems to get into, although we will probably manage a tweak. Once the Progression is perfect and the WOT is optimal, then all the remaining problems are atomiser or slide or main air corrector. Now, changing any of these will mean going right back to the start with the jetting at progression and WOT before coninuing again with the atomiser. No one said it wasn't a lot of work. You can see why the standard engine is the preferred tourer (although slow by comparison).
btw; on your diagram the atomiser is upside down and there are 6 rows for holes.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
H, 'Bimbling'!! - behave yourself! - not in my back yard.........
Loon-e, yes it's finally playtime. - I'm ready; all eyes on you now..........
Jim, you seem to be jetted a bit leaner and running a bit hotter than mine is; I'm still tweaking-down, but don't reckon I'll settle on 170ºC. No need to remind me it's Summer down-under; I lived in New Zealand for five years and always think how great it would be to still be there at this time of year. Been watching the Tour Down Under (Adelaide, which is cooler than Queensland) and seeing the sweltering conditions; you'll get yours though – Autumns just round the corner for you!
Pxguru; I put the 140mj in last night, ready for this afternoon if I get a chance to have a ride to see what my temps are like; hopefully get a bit more 'optimising' out of it before shelving the job; it's mild and damp again now though, but my weekend is quite busy – a range of chops, MD & 0-60 for a reference/benchmark soon too (that's why I did the 140). I had to increase the Idle a bit with the new seat, so I really do need to redo mix and Idle screws first as well, because I've lost track; the mix is still at 2, but I've wound the idle in a couple of times with recent changes, so need to start from scratch and get it spot-on again. Yes that seat is a bit hard; I only had a quick ride on it yesterday to see if it was strangling the air. I'm keeping the old seat for when I'm loaded-up, and I've got my eye out for a good, bigger stainless rack to carry a tent and stuff; that rusty chrome one had to go though, and I do like the look of a race seat with a little stainless Lammy rack on it when I'm just buzzing around locally. My scoot was imported about ten years ago, which I think is why it was an EFL engine so early (1983); that's why it's a kmh speedo too, and with it showing 80,000km now, I like it being original. I also think my frame is pretty un-rusty for nearly 35 years old because it spent the first twenty years of it's life in olive groves and vineyards! (maybe) I don't use that speedo anyway, it is waaay out; when accurate speed is important I clip my phone on and use the GPS readout. The fuel gauge doesn't work either - all that speedo does properly is the warning lights for MOT time. As far as changing atomiser, slide, or air corrector involving more work is concerned; I really don't mind at all. I know this carb is taking a long time to set-up, but doing any of it quickly wasn't part of the plan; the whole idea of the build from the beginning was to do it thoroughly and to learn from doing it (and as it turns out, to make a pretty decent engine in the end too). This carb subject in particular was something I knew I had no idea about other than the MJ; it isn't just the finished engine that marks the success of the job, it's what's been learned during the making of it. Having said that; maybe I'm a bit jaded with it, and a break from tweaking in the wet and frozen conditions might refocus my concentration for the last stages too. However; If I've got that atomiser up the wrong way, it is simply because I'm a tit! I gave it lots of thought, thinking about my animation and fuel levels in the stack as revs increase, and which holes were uncovered; if I've got it wrong it means I need to read-back about what happens in the stack because I've got that wrong too in that case – I thought I'd sussed it (I've pictured fuel rising with revs, so fewer, higher holes being exposed to lean the mix – I'm the wrong way round aren't I? - it's dropping then? More and lower holes exposed? That makes more sense too - I will check; I know we've discussed it, but I've remembered/understood it wrong). I will put my sketch right before the days out so as not to mislead any later readers. This seems to be a bit that I still haven't got a grasp of – yet.
Apart from that, it is now Fun-Time; rabbit chasing, sheep dodging,........................
Hopefully the plug will now be a shade lighter all round, then you are good to go till Spring.
The atomiser is a tricky thing, as its all inter-connected with the rest of the carb. Here is a simple version of how I see it; Once running and the throttle begins to open the atomiser level will rise to its maximum (hole position 1 of 6). As the venturi flow increases the atomiser level will begin to drop as vaporised and emulsified mixture is sucked out. Combined with the increasing venturi flow and the MJ progressivly gagging off the fuel source the level will drop to its lowest level (hole position 6 of 6). The holes are spaced linear but unlikely that the level decay is linear as it would depend more on how many holes were already uncovered. Any clearer? This should be enough to get the diagram working right.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I was hoping to post a better set of results than this, and I was tempted not to post, but I'm hoping that showing them will help me fix it, so we can put these ones behind us and show better ones.
I don't think these give a good picture of the engine at all, but I do think they might help me sort out a bit of a problem that I seem to have developed since recent changes.
I've got a real splutter and flat-spot in 3rd at about 3,500rpm. I didn't have it before with the 142MJ. As well as changing the 142 for a 140, I've also fitted this seat, which I think might restrict the airflow. I'm still not getting high temperatures either, which suggests I'm still rich. I've got poor acceleration in 2nd and the low-end of 3rd. Also I held it open in 2nd at one test this morning, and it really died on me up the revs too. Possible causes then: 1) 140 is lean after Progression where jetting starts to include Main Jet. (3,500rpm), but it passes that point and is back to normal higher in the revs. 2) 140 is rich after Progression where jetting starts to include Main Jet. - I know I should be able to tell the difference, but I'm not sure what spluttering at 3,500 means – air or fuel; I've put the plug below, which looks lean, but I deliberately didn't have a lot of petrol to do the MD run, so couldn't give it much of a ride first on the new plug to get much colour in it; it's just the plug after I got home from 20km or so of testing - there's more colour that this photo shows, but not much; not a long enough run on a new plug again probably:
The torque is impressive. Not really any less than the standard kit is a good achievement. I get the feeling this MD run is no good though. Should be more like 15. I would do a few more runs before believing this.
1. If you take off the rubber hose on the carb box it will rule out if the seat is any issue. I would doubt the seat is any factor but you never know, I have seen this before.
2. Put the BGM 142 MJ back in and see how it goes. That INC 140 MJ might be a lot smaller than the 142. It all sounds like it might be running too weak.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Thanks, pxguru. I'm glad you like the torque anyway; the peak might stay as it is, but I expect the low-revs to be better when I've sorted this out too - that curve is wonky too. It strikes me that if I had a good, even PS climb (green on sketch) like I had before on O.F. (though shallower on O.F.), and like I felt I had with this engine last week, - in the film before the last two changes -, then the PS will go where it should.
The clutch could be slipping but if you are not sure now, it will develop then there will be no doubt. When accelerating hard in 3rd and 4th it is usually the most obvious.
edit; I think analysing this MD is not worthwhile if it doesn't feel like it is running right.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Righto, thanks. Just to tidy up then, before I move on to sorting the spluttery low-running I've somehow created recently: I don't particularly think my clutch is slipping, and wasn't intending it to read that I thought it might be part of this problem; I just thought it might explain the discrepancy between calculated max rpm speed and measured max GPS speed, which wasn't particularly important; just had me curious. BUT; I am going to disregard this MD result above anyway, so the numbers I was trying to make sense of above don't matter; I'll just concentrate on getting good, strong, smooth running and acceleration through the rev range again like I had last weekend, starting with going back to the 142, and making sure the seat hole isn't giving me a problem. - Smooth through the range; check speeds/temps/plugs.
She cannie take it Captain!!!! (The clutch, that is).
Uh oh! - You've got me suspecting my clutch now..... I pondered overnight, and made time this morning to do those two jobs: ## Changing the MJ back to 142 made no difference; I got my static idle-rev-idle right to be sure Pilot was still OK, got it riding nicely at low revs, and I've blown the jets out too – I'd have to take the carb off to check the MJ well where I drilled though. ## Removing the carb box hose made no difference either, so the seats in the clear.
Whilst riding in the lane to test this morning, I'd say that it has got more noticeable, and in 2nd to 4th now too. I was trying to decide if I thought it felt like it could be clutch, not carb, and I can't be sure, but I think it's possible; it sort of drops and surges then picks up and is OK for a bit, but now maybe it's developing in high revs in 3rd and a bit in running in 4th too, but it is hard to say if it's combustion or transmission – wish I was more experienced and could give a better diagnosis here. - Would the revs race if the clutch was slipping though?
I suppose the only way to be sure is to have the clutch out and have a look at it, which is a drag, but if it needs doing then I'll have to get out and do it. I could try it on a big hill, but it's a long uphill walk home if I break it.
Can you think of anything else to test to make diagnosis more reliable before taking clutch out? I suppose if I put carb back how it was on Sunday, and if the run was obviously worse it would confirm – but it might finish the clutch off too!
I've got mixed feelings about this; it's good to explain the poor acceleration and 12PS on the MD (which we're ignoring, but still happened), it's a pain in the arse fiddling with clutch and buying more stuff, but it's best to have the aggro now, rather than mid-scoot season, or a breakdown on the road – I don't tend to carry a spare clutch (yes I know some hardened scooterboys on here do; good for you!)
That's me for now; the heart sank a bit as I realised I might have buggered the clutch already, but if it needs doing, I might as well crack on with the job......
(Thought I was ready for Spring, but seem to have given myself another hurdle first)