Imola 186, Dellorto 28mm, jl3 Snail-Dyno results-feedback...

[kev]

Just had the chop on the Dyno after messing around with jetting etc for 2 weeks :baddevil:
Original problem was it would not tick over, and when fully warmed up would race for a while on idle before settling down and dying
Tried every combination of main jets, needles and atomisers, and pilots from 48 right up to 60
Although the racing has now gone, tick over still erratic, and she doesn't seem to pull as well, its not boggy, just not as rapid on acceleration as before dyno
And after a run the casings seem red hot, it also smells hot, have done plug chops and colour is fine.

set up
Imola 186
28mm dellorto reed valve
JL3 Snail

Carb setup after Dyno
122 main jet
X7 needle 3rd clip from top
Av264
60 pilot

Just after a bit of feedback guys please, as have been advised by Dyno guy to go up to a 64 pilot, and ive not seen anyone using one any where near this big..

[drunkmunkey6969]

I'm a bit confused, you say performance is worse than before the dyno? So which is the before and after line on the above graph? Surely performance must be better if the light grey is before (12.76) and black line is after (15.71)??

What was your jetting spec on the before graph?

Also, do you run an air filter? And what is your ign timing set at?

I must say, your main jet looks a smidgen too small for my liking, and the pilot sounds too big...........are you sure you dont have an air leak????

[kev]

Cheers for reply, been off line for a few days.
Black line is after dyno, shows a marked improvement on paper, and although doesnt bog down now, just does not seem to pull as hard through the gears, acceleration seemed alot more rapid before dyno, if that makes sense.....
Cant remember exactly what carb set up was before dyno, but think it was probably as dynod but with 266 atomiser and on second clip with the X7
Took it out this afternoon, just doesnt seem to pull as hard, idling at traffic, having to blip throttle for tick-over, and occasionally will splutter when doing this.
Still on 60 pilot.
Thought about air leak, have replaced all gaskets etc.
What i think im trying to ask in my ramblings is it should be ripping my arms off when i open it up i think....

[kev]

I'm a bit confused, you say performance is worse than before the dyno? So which is the before and after line on the above graph? Surely performance must be better if the light grey is before (12.76) and black line is after (15.71)??

What was your jetting spec on the before graph?

Also, do you run an air filter? And what is your ign timing set at?

I must say, your main jet looks a smidgen too small for my liking, and the pilot sounds too big...........are you sure you dont have an air leak????

Turned out not to be a carb issue after all, out yesterday when scoot backfired, coughed, spluttered and died, smelt like it was running hot and when attempting to kick back over, kick start would travel down, but when at end of stroke would recoil and nearly take my leg off... on third kick would backfire, suspected woodruff key.
Try pushing a 9 foot chop home....so embarrassing...
went to take flywheel off and found nut was not even hand tight, and wood ruff key had sheared.
All back together again last night, and now flies again.