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Post by pxguru on Feb 16, 2015 7:08:20 GMT
Glad to hear it was running so much better that you didn't want to take it home!
It should really have another 0.5mm out of the exhaust port before it is near enough to minimum blowdown to leave it. Don't worry about the slight tool slip, if it's just near the exhaust port, won't make any difference at all.
If you are happy with it as it is then get some use out of it for now. I doubt another 0.5mm will affect the bottom end enough to notice but is probably costing a few HP at higher rpm. Often as the high rpm gets more powerful and later the mid torque starts to feel weak but isn't really. Run the MD and I expect you will see what I mean. If you do get a programmable CDI then the mid range could be improved further. On my programmable CDI I have the static ignition timing set at 26.5 degrees, when running up to 4000rpm to max the mid range. After that the timing reduces progressively to avoid any melting anything.
Run the MD again and compare to the original and see how the curve shape is now.
Edit: If you raised the exhaust port another 6.1mm from where it is now then you would be on the limit of your transfers. Another 3.1mm from now would be tuned for thrashing on the road.
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Post by henri on Feb 16, 2015 16:38:47 GMT
yep i know the hill out of guildford , nice down grade , an its funny what ya think as the tarmac tears the arse out of ya jeans , my best is in greece an a surprise tortoise encounter , an as i slid all i could think was " bloody hell the sky aint half blue ere " , so your CHT alteration seems to be working an a success , reckon i might copy ya on that one , an only just on MJ at 55 eh , might be time to fine tune the atomisers as there going to be runnin the mix a bit more ,unless your plannin on pure WOT riding , good news all over tho ,glad for ya , H
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Post by vespasco on Feb 16, 2015 18:28:49 GMT
Kool! I did actually plan to take it to at least 36mm, a nice round number, within the rev range i wanted, but it started to get dark, then i noticed the little slip i made too, so called it day. It wasnt too deep so i think i got away with it. I appreciate it could do with a little more but i think its good enough. Ill know for sure when its tweaked to within its limits. Im hoping the little loss the of mid range i felt in mid range was due to the slight head wind. I was also hoping it could be down jetted. No plug chops as yet. If the penny jar gets full again (after being empty by the bgm clutch)! then i may just buy one of those cdi add-ons. I like the fact it will still work, even if the electronic gadgetry fails. I dont like to rely on gadgetry too often. Keep the Vespa simple, thats my aim. Or it was until i got tunititus! Although ive not actually added anything to it - the motor is still in its basic, simplistic form, so i think its still going to just as reliable. How long have you been using yours Guru ji? And 26.5°! Nice! That should be pretty quick off the mark! And thats the next thing im going to try...advancing ignition When the kit has almost finished its life, i may, just for fun, raise it to buggery as you suggest Hows your malossi coming along? I bet that things full of holes!! When we were 'slowly' sliding down the road my mate turned round and casually asked, "you alright"?, i looked at myself, noticed my shoes were kissing the tarmac, adjusted position, said "yeh". Slowly the scooter spun round on its side panel.. 'Oh look! theres a van! Man, wife and his kid in the front', if i went under hynpnosise id probably be able to recall the reg no. and tax disc date!! Hahaha! It all seemed to happen so slowly! *No tortoises were harmed in the making of this tale. Cht sensor....so far so good. The actual threaded, sensor part is VERY fragile! Be careful, ive broken 3 of those already! Quite a few rings too. Its a weird thread size on that thar sensor! 0.8 pitch x something like 4.3? I drill a 4mm hole. All my taps are the starter type so i had to use a new bolt (5mm) to finish it off! 5mm is not ideal! But with loctite its stayed in so far. The fin where i drilled it is not really big enough to tap a hole into tbh but you can get at least 5 - 6mm into the actual dome. Guestimated figures. Its working so far anyway! Basically, tap it as deep as you dare/ need to, to get a bite. I found out if you use loctite and do happen to snap the sensor (easily done) you will have to drill the sensor out! Ahem! So thats the down side. Once its in,its in! No more plans to ride wot where i can. Not anymore, that experiment is over. And a success as far as im concerned Im happy doing 60mph at around 1/2 throttle everywhere, more mpg, which before was 63mpg. I have that little extra too, enough to be able to overtake lorries. Isnt that what most people really want out of there scooter? Enough to be able to safely and comfortably keep up with the traffic? I may even decide to keep off the motorways from now on too! (After i done my complusory, try-and-break-it final test - once around the M25 at full wack). If it can handle that with no worries then I'll be confident in the knowledge that i can go anywhere on it. Motorways are boring but have their uses. So, first, advance timing, get that right, to its non-pinking peakiest! Then i'll try coming down from the 140MJ. Plug chop. Repeat as necessary!! I have a couple of different slides and mixers but hope it wont have to come to that!
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Post by pxguru on Feb 18, 2015 4:49:16 GMT
As you are happy with it now you might as well leave it until its apart again or you decide it needs some more top end. You are still quite a few mm away from having trouble with a 3rd to 4th gear gap (similar to what always happens with those Malossi 210s). Have to keep remembering yours is a Rally frame as well, even less suitable for motorway speeds than a PX!
On an engine tuned for high rpm power, the programmable CDI is one of the many little tricks needed to help get the mid range back up to normal. I've had this type of CDI about a year and after a few seasons of tinkering and porting, I have pretty much finished my Polossi. It will now go up hill at 30mph in 4th like a standard engine or roll on to over 8000rpm, overtaking the cars on the motorway (only if there's no cross wind, as that can get properly scary and tries to do something like a tank slapper, when overtaking white van man!).
Hopefully you won't need any of the different slides or anything but BE3/160 as that would be unusual for a set up like yours. The 140 jet is not 'way' to big, so be careful to get it really hot and watch the temperature as you hold it at wot. Only reduce the size of the MJ if the temp drops while holding at wot. Otherwise leave it alone. On an SI the main jet affects the mid range too (as adjusted by the air corrector) so looking for slightly rich colour as always. Check the plug colour at 1/4, 1/2 and 3/4 when you are done. Then ride all summer without touching anything more!
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Post by henri on Feb 18, 2015 10:22:34 GMT
as above , my spidey senses are saying bulk purchases of b7 plugs n multiple chops at diff revs are in your near future , get it finally exact dialled in an leave it there , summers coming , ride the damm shopping bike ,an bugger motorways on a scoot ,too many speed-freak bulgarian truck drivers on them , H
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Post by vespasco on Feb 18, 2015 19:14:07 GMT
Roger that! One of my bench marks is also smoothly going uphill in 4th @ 30mph and crusing on a flat road in 4th at less than 30mph. Although mine doesnt rev so much as yours so Im guessing that took a few good attempts to nail it! Before my rebuilds my motor was constantly in 4th from 25mph-70mph+. Loved it!! It was like an automatic! That '74 rally doesnt like it much over @ 70mph, especially if i find myself in a slip stream. Its enough! Most of the steel in the 70s was pretty crap too! ... I think ill try and stick to the inside lanes a bit more from now on! Id expect/hope not to change the jetting too much (or the slide), but they're there. Im sure i can come down to 138 or 135mj. Considering it was always spot on @ 130mj (but could have still managed @ 132mj ok, with the be3/160) Your spider senses are working well H. Id already have a couple of plugs ready from last time! Seat of pants tells me the 'first' results, when thats feels good enough then I will be checking the plug colour, marks. When it all feels nice and i think its v v good , then , I'll do a 'proper' plug chop. I ve always ran B8 plugs on this motor although 7 would be ok for burning around town. I cant wait to get out there again and get that thang fit enough for traffic light shenanigans too! I dont go out looking for it but it often happens.... A couple of young lads in a hot hatch pull up beside me, waiting at the lights, revving, laughing at the Vespa. I remain cool, bolt upright, the vespa ticking over slowly, thinking..."i bet i could"! Lights turn green, we both race off, i normally end up side by side, laughing my arse off in their faces, as their hot hatches cant even beat a 40+year old vespa! Funny as f!!! If my new Vespa can still do that, and still ride wot all day if it needs to, then i aint ever gonna touch it again. Not until next time ;D
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Post by vespasco on Feb 21, 2015 20:12:45 GMT
So far. I advanced the ignition to about 21° (I'll measure it when i finish tweaking it). Pinking again! Just like last time. So then i filled up with petrol, this time at my 'usual' petrol station and used my 'usual' oil and guess what....no pinking!?!! Wtf?! (Last refill was out of town and with different oil) So its either the fuel/oil mix,,, or the bgm ff tap and new fuel pipe ive recently fitted are not getting enough fuel to the carb when the tank is on reserve??! (But its never been an issue before with the stock tap) I still havent ruled out its leak free yet either. Anyway, with ignition advanced pick up is better, as expected. Top speed and getting there is better too But...i do have a flat spot in mid range, more so than ever before. Its like its lengthened the gap between 3rd and 4th if that makes sense. That could also be a too large MJ?! Ive noticed too that the motor doesnt seem quite as responsive in 4th as it once used to be. Now if i wind the throttle to the 1/2 way mark it will sometimes take a while for the motor to catch up. And if thats going uphill with a head wind, then im not do sure it would catch up. Ive got to change my style of riding to suit it at the moment. Ive still to fine tune the jetting as yet.. I took my spares out with me the other day, ina little bag, 52/140 and 50/120 idles and MJs 130-140 and 190AC .. i cant find them now!! Argh!!!! So, what are my mid range tuning options? (Without dremeling)!
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Post by pxguru on Feb 22, 2015 5:51:12 GMT
21 degrees timing is much more like it. The flat spot is probably the MJ. Is the float bowl all standard height? No packer on it? When you find the bits carefully reduce the MJ. Always check the temperature to verify what is happening. Seat of the pants only gets it so far. Keep that 190 air corrector lost. Running that on your set up will hole your piston. I suspect there is something funny with your head causing the pinking. It shouldn't be so sensitive to petrol. Do you have dowels fitted to exactly centre the head over the piston? This is more important with tighter clearance (about 1.8mm or less) and the squish starts to perform properly (doing actual squishing). Pinascos have big 69mm pistons and if the head is not centred then this could be the whole issue. It will need a little more out of that exhaust port before it sets up really well. You will see on the MD curve it still flattens off a little too early. Sounding like good progress overall though. 55/160 160/BE3/~135 and 21 degrees should be about it
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Post by henri on Feb 22, 2015 10:34:20 GMT
i'm sorry pxguru but i'd disagree about the petrol ,the quality an % of ethanol in modern stuff is atrocious , an also theres a higher % of water contamination aswell , the ethanol sucks it up an then it emulsify's on any fuel filters in the line .an also i'd still advise runnin a tad more retarded an learning to live with it like that , as 40 year old engines/designs wont ever be right on the money with modern fuel, ive been wondering wether a lead replacement additive like whats used in 4 stroke older cars might help, piaggio says its 2 strokes are ok on unleaded but ive never heard them claim there as good or better than when running leaded .an thats the fuel they where designed for ,i dont mean a octane booster additive as i reckon that would worsen your woes . do agree totally with guru's comment on centering the head ,to get a correct/even squish , an have you pinned down where in throttle range the flat-spot occurs ,just upto an half throttle =atomiser ,from an higher half =main jet ,an you saying youve got to feed in throttle not just crack it in anger makes me suspect a tad overlarge main jet , H
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Post by pxguru on Feb 23, 2015 3:17:01 GMT
H - how could anyone ever say modern petrol is any good? My point was if it starts pinking after filling with different petrol then there is something making it too sensitive. This is not normal on a non highly tuned Vespa. Should be able to run it on any old cheap c**p and it wont detonate!
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Post by henri on Feb 23, 2015 10:51:47 GMT
true ,its got to be on edge of its "comfort zone" to react this badly/instantly , H
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Post by vespasco on Feb 23, 2015 15:39:12 GMT
Ive taken it out for a spin again yesterday. It pinked once, slightly, so, i ran the tank almost dry and refilled with my usual mix. ($hell premium and putoline fully synth, as thats what my local vespa shop keeps in stock and its nice to pop in and say hello etc. After 2 hours of riding, freezing my nads off it didnt pink once. Not even uphill into head wind. It was again too windy for dynos but with back/side wind 74mph, in the opposite direction with head/side wind i managed to slowly ease it up to 64mph I even tried a new gps app too and it actually agreed with my sip speedo! I never did trust sat nav speedos but this one might actually work!? I know it doesnt really count - with a back/side wind but it does still prove that the motor has impoved with all the little mods. The flat spot (and to a certain extent, 3/4 to WOT) does show signs of a too large MJ so when i find them bloody things ill let you know!! Ive already ordered some SIP performance jets. Why i didnt stick to dellorto originals I'll never know! Theres no spacer on the carb. I looked into those before and decided they are a bad idea and would alter the way the atomizer works. The head could be off a tad.? Its possible. Only lined up by markings. Ive been waiting for a friends dad to make me some stud sleeves.. But dowels maybe the way to go. Its possible i may just have the right pieces laying around to do just that! Im finding the tighter the squish and higher the compression the more sensitive it becomes its true. I dont really want to start mixing and changing fuels but youre right, it should be able to run on anything. But i will be setting it up with and using premium fuel, close to the edge Both garages were Shell, using Shell premium,less ethanol in premium. But i did use a different oil (fully synth) $hell stuff. On these odd occassions; when temps go high, it pinks, lacks power, i do still wonder if there is a minor crack/leak in the cases. Im happy the head is sealing but not 100% sure its centered. Flat spot around 1/4 - 1/2. The main will also affect this so im hoping once i get a smaller mj in there it will help. Ill be trying my utmost to keep the BE3, with the 160
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Post by pxguru on Feb 24, 2015 10:50:40 GMT
I would think this is just about fast enough for a Rally frame. A smaller main jet should fix the flat spot. Weaker running makes more power so should improve all round. Stud sleeves are the best way. If you are taking the head off then, could get another 1mm out
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Post by vespasco on Feb 25, 2015 11:22:46 GMT
Yes..this is certainly fast enough for a '74 Rally !! I still havent found my Dellorto jets and I'm still waiting for my new jets to be delivered..... Which I ordered from SIP from some strange reason, which takes 5 days!! I should have used Scooter Centre, they would have been here by now, and would have been genuine Dellortos!
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Post by henri on Feb 25, 2015 12:25:56 GMT
i used sip last set of jets i got , 1 day to get to gatwick an then they disapeared ,ups , i told sip after 5 days an they resent nxt day ,told me by ups again , turned up 2 days later by dhl , was christmas so not too bad , then 2nd of january sip refunded me 19 quid for the lost set , even tho with postage they came to 16 quid , might of been 19 euros then . am still waiting to see if theve the nerve to ask for money back, so final score is 2 world wars,1 world cup,an a set of dell' jets , result , H
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Post by vespasco on Feb 28, 2015 21:27:30 GMT
you jammy .... Henri! Update. jets have arrived. i went straight for a 135, from the 140, to help me notice the change more easily. everything felt good, ran well. no more pinkng by the way. i put that down to me not flushing out the ports properly from the first grinding/porting attempt. who knows. its back to normal anyway. i done a quick plug chop at 1/2 throttle into head winds. firstly i forgot i had my old (iridium) plug back in, which has had a few 1000k on it. Here... i know its black, thats not a problem atm, but the first thing i spotted was the yellow porcelian and the white electrode..which this pic doesnt show so well..... that alarmed me quite abit, i wasnt expecting that, so i put in a 138MJ. normally, at WOT, that plug would be a burnt bourbon on the biscuit scale, which im ok with. The 138 still repsonded similiar to the 135MJ so ive left that in for now. same speeds as before - 73/4 one way, 65 t'other in these wet winds. I also gave the idle mix screw a tweak, further out, to enrichen it a little. I need to get some miles on those new plugs and check it all out properly. and the timing could possibly be tweaked but im quite happy with it where it is atm. * note to self - measure the timing!! But it was pretty chitty weather today, wet (although not really 'real' rain) and 'Quite' windy. Thats a technical term btw. it means hang on a high speeds, dont reach down to kill ignition @ WOT! (mines a '74 Rally, with ignition near the seat hook) still no pinking agianst the wind, uphill, not that i could hear in my windy, mandatory open face crash hat anyway. its probably not much use in this thread but because i could and actually did, here's, pretty much, how i like to have my idle set. its not 100% atm but hopefully it shows, 'roughly', how long it should take for the motor to die down after you blip the throttle.... theres a little improvement in responsiveness to be had if i advanced the ignition a 'tad' and went back to the 135...and made it rev a tad higer at idle-this im going to do,,,,, we'll see....hopefully heres a short vid of what i mean.... edit: no vid? it wasnt meant to be?!
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Post by vespasco on Feb 28, 2015 22:38:42 GMT
Hopefully, heres the por...i mean video...
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Post by pxguru on Mar 1, 2015 3:26:36 GMT
Sounds like its much improved. Really need to use new plugs for a plug chop. get it hot with an old one then fit a new one for the plug chop run. That one looks confusing but generally weak, so be careful. When taking plug pictures be sure to show to the bottom of the plug right down inside.
How do you adjust your mixture screw? And are you still running the 55/160 pilot? How does the plug look at WOT with the 138?
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Post by vespasco on Mar 1, 2015 11:12:17 GMT
Yup! Definitely improved! Sounds much louder/meatier too! My local vespa mechanic was confused to hear such a noise from an old vespa!! Hahaha! See vid above ^^^^^ The smaller MJ has also improved across the whole throttle range. The flat spot is still there but barely noticable. Ive also got to change my style of riding slightly. Before i could confidently wind the throttle open in 4th from low revs and it would pull smooth and solid, like an auto, without worry of a flat spot. Now i have to be a little more cautious when winding it open from low rpm and sometimes have to drop down into 3rd to keep the revs up. Then again , it could just be the strongish windy weather. As for revs...all gears hit the max speed in the gear calculators. I cant ask much more than that!! Now its just a matter of fine tuning. That plug is confusing, being old etc,,, i thought i still had a new one in there. I probably should not have posted that pic really. But it adds another flavour to the range - custard cream bourbon!! Or Oreo!? Hahaha. Im waiting for a day without wind (I should lay off the beans and lentils)! to do a MDyno run and fine tune it. I never can get that shot of the bottom of the porcelain, so thats as much as i can show. Suns just about out, still windy tho' New plugs will be fitted today and taken for a test run. It still has the 55/160 in atm. I have 52/120 and 50/140 to play with. (I used to use the 50/140 all the time, no worries). I set the idle up as described in the thread.... 'Ebay exhaust'...as below, roughly.... ...Personally, i listen for when the pulses speed up. Something like this,,, Starting from screw all the way in for example, i turn it out 1/2 turn, 1/2 turn, wait for motor to settle, 1/2 turn, listening very carefully for a change in the pulse and to famalairize myself with the sound of the pulses, blipping the throttle, checking for responsiveness, clearing the fuel. Another 1/4 turn, again listening for that subtle increase in pulse, blip throttle again. Another approx 1/4 turn in or out, *to find that place where it pulses fastest*...then starts to even out. Then keep turning in/out very slowly, 1/8 turn at a time, to the point where it just begins to stop pulsing so fast/ it pulses evenly. *THIS is where the sweet spot is* (thats what i believe anyway)! Its all very subtle so listen carefully. Its also hard to explain! I havent done a WOT plug check yet...hopefully today ill find out! And not get so wet! Well, the sun was out! I'll put on another laying of clothes and go get the Vespa dialled in once and for all. Hopefully. Although, once its set up nicely,im going to try the sip mkll pipe, to compare against the mkl. The sip mkll is supossed to give more power just where ive been lacking it of late. So it could be quite fruitful!
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Post by sime66 on Mar 1, 2015 12:18:44 GMT
Ahh the biscuit scale – time to dig that one up and brush it off for another showing! You’ve introduced a new colour – especially to match the forum colour – well done!! It sounds splendid; not like an old Vespa though, more like it should be on a race track.
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Post by pxguru on Mar 2, 2015 4:15:49 GMT
If you change the exhaust after it is set up correctly and it does go better, it will mean that it is now running leaner and will need up jetting. so again be careful to listen for the pinking. I have probably written this before a few times. Feels like I have. Everyone has a different way but right or wrong this is how I adjust the mixture on an SI carb. Start it up get it fully hot. Turn the mixture screw out a lot (approx 4 full turns). Turn up the tickover to about 1400 rpm. Check it is smoking too much. Slowly turn the mixture screw in till the revs increase noticeably. Wind the screw back out until the revs nearly drop. Turn it back in a bit and that's it. Stop the engine and check how many turns out. If between 1 and 3 turns the pilot jet small number (ie. 55 form 55/160)is ok. If it doesn't smoke a lot at 4 turns, the pilot jet small number is not big enough. If the revs don't increase until about half a turn out the pilot jet small number is too big. If your 1/2 throttle plug chop is lean on a new plug you might need to fiddle with the BE3. Let's see how it goes. Sounding better is good. Did you take any pictures of your exhaust port shape on the top edge? Digestive is still the preferred biscuit!
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Post by sime66 on Mar 2, 2015 9:43:40 GMT
We already had to stretch the lean end of the scale for BigD's contribution last year; as creative as it is, I don't think we should encourage 'vespasco' yellow.
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Post by vespasco on Mar 2, 2015 21:58:05 GMT
I think the fact it sounds meatier is because theres virtually no air filter mesh left on the stock filter i have. Apart from the, ahem, modifications ive made. But it has made me want to check things closer, as its quite a change and youre not the first to comment on it. Im tempted to try a new stock filter (drilled heart etc) which i have anyway. Would quieten it down a little too!? how it will affect the flow im not so sure exactly. But may just richen it a tad/enough in all ranges!? All this tunititus may even tempt me to fix my old exhaust, i think it could be a much better match for motor now!! But now im getting carried away! I need to get this right first. Trouble is I cant really fine tune anything in these winds of late. Im still waiting for a calm day for that. I think theres a good reason there are lots of windmills around here. Believe me, cruising at 55mph-ish at no more than 1/4 throttle with a back wind, especially when going down hill, and when setting up the carb after mods' is not so much fun but temps didnt go wild. There is really only one way to get more fuel in there to prevent a seize, (alright at least 2 - pull choke out) and that is to give it more gas!!! Yeh baybee! Fly like the wind! When theres a safe place to overtake! (Alright, maybe 3 - drop a gear)!? I done a plug chop, just hadnt had time to actually chop it down to have a sneaky peak at its, no doubt, lily-white-ass, non-existant ring. Its good to get a variation on the idle technique. I'll certainly try that too. So if i had a 55/160 and wanted a larger fuel jet size, do i have to make my own? Id much prefer a 60/160 for example, than say a 50/120 but have never seen them 60/160 for sale anywhere. Ive not got the tools to drill one out. It makes more sense to me to go that way. Id expect to tweak jetting if /when i swap exhausts. *Those carb spaces i never did like 'could' actually be advantages in this instance!?! No pics of the port, only one 1/2 through. Its still close to the original shape. Radiused arc. Haha I knew i shouldnt have posted a pic of that ol' uglyplugly! But it is quite odd looking i have to say. It'll be back to a fluffy bourbon soon enough . *i might even give it its own blog, so you can all see the progress it makes. Heres plug no.8, on day 1, all lean and weak..... I'll update with some pics when i get some time.
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Post by pxguru on Mar 5, 2015 3:10:24 GMT
I'm not sure what monster of a scooter would actually need a 60 pilot My approx 33bhp 221 has a 52 pilot and runs really well low down. My last 210 ran a 55 in a Spaco SI26/26 and that was about right. Yours does sound like its going well though. What other 55 pilots do you have available? I am sure the 55 won't be far off but the 160 part might be too much and making it a bit weak as the revs pick up.
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Post by vespasco on Mar 5, 2015 21:59:32 GMT
Before it always had the 50/140, which i may put back in as its always been good for the motor. Although I do also have a 52/120 I'll need to do some more test runs to dial it all nicely. I still havent had the chance to get conclusive results. (My work is so busy atm and the weather's been so windy). Interesting to hear the si26 is an ok carb for a tuned motor. Ive thought before about putting one on mine but couldn't decide if it would be of much benefit against the money it would have cost. I was worried about the flow actually slowing down with the bigger carb. Yeh well. Then theres also the T5 carb whch was also a contender for my motor but heard they were difficult to dial in on 200ers so left that one alone too. (Also the fitment in a Rally chassis wasnt so good), so just made the stock si24 work, and work it did and work it shall! So if i was to alter my inlet...adjust the .... Wait! No! I need to get this running real sweet first!! Thank you pxguru ji
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Post by sime66 on Mar 6, 2015 4:35:53 GMT
All these carb options; I reckon we need to explore the subject a bit...........
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Post by pxguru on Mar 6, 2015 5:57:03 GMT
When the pilot jet is the wrong size it makes the whole set up confusing. With any type of carb its the first thing to get right. Before any other jetting can be right. The old "layer cake" senario....you have to start at the bottom and work up. Have a go at setting your pilot using my procedure. See what you end up with on the Small number (probably 52). Setting the big number on a pilot jet is a different procedure Warning small rant coming - Often pilot jets get the same treatment as plug numbers and incremented by one every time some new bit of kit is added, without checking to see if the engine actually needs a bigger pilot or colder plug! Next time you rework yours you could go for a 26/26. Big advantage is for keeping autolube, so as you premix, you might as well get a 28mm . As it is now you are so close to being able to just use it all Summer long, there is little point changing it now, decide next Winter.
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Post by henri on Mar 6, 2015 17:01:41 GMT
agree with the above ,most dont realise that pilots still flowing fuel after the atomiser then mains taken over control ,so discount it , as guru says it needs to be right before startin on the others ,as if ya set main first then fiddle with pilot you'll prob have to re-fettle the main , ever decreasing circles til disapearing up ones own fundament , as pxguru says , spring has sprung ,boing, get it ok-ish then ride it like ya stole it , H
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Post by vespasco on Mar 10, 2015 23:01:48 GMT
Heres an update, better results, not so windy! This is with sip mkl, 52/140, 138mj But was not running so well. I have other queries, ill start another thread. This Fred is Dead (But not forgotten)!
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Post by pxguru on Mar 11, 2015 1:57:58 GMT
Good progress Looks like a power increase at least. Needs a little more blowdown to let the horses free! Starts clipping at about 6200 because the gas cant get out in the time available. It's not much improvement power band wise than before but from your writing I think that you feel overall its faster. If you got this turn down point (top of the power band) moved from 6200 to 7000 it will pull the whole range up. Also as you are after similar performance to Sime66 I would suggest that you should copy his exhaust port shape on the top edge. The sunny days are coming and thats when the work stops and the riding it begins
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