SX150 flywheel not always turning when kickstart operated

[george4422]

Hi, looking for a bit of help!
Just rebuilt the SX150 engine (Mugello 186, Scootopia 22mm carb, Ancilotti, SIL ignition) and nearly everything else brand new, to original spec.
Engine ran fine, then it started revving and no power, so split the cases and noticed the front sproket had just worn away
over its ramp section. (Looked like a real lightweight/poor quality item that was re-used).
Replaced that with an Innocenti item, checked clutch, chain, etc and put it all back together, and now after the first two/three kicks, the flywheel does not turn and there is no compression...

All thoughts/suggestions would be appreciated.

Thanks,

George

[cgt75b]

Hi mate
Sounds like a slipping clutch to me.

Good luck with it.

Lambretta's a right pain in the arse lol.

[garry inglis]

Did the casalated nut tighten down properly if so I would look at the woodruff key on the crank probably sheared


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[bristolmod]

+1

[theageofindustry]

If you have no compression when you kick it, that is 100% clutch related. The flywheel is only indicating that the kicker is not turning the crank over.

I'd guess either your clutch cable is too tight causing the clutch to slip or your kickstart quadrant is noy shimmed properly and has walked out of the chaincase cover amd is rubbing on your clutch which would cause it to slip.

First thing I'd do is just unhook your clutch cable from the clutch arm and see if that fixes it. If that doesn't do it then you'll need to open the chaincase again and figure out why your clutch is slipping when you kick it.

[bristolmod]

If you have no compression when you kick it, that is 100% clutch related. The flywheel is only indicating that the kicker is not turning the crank over.

I'd guess either your clutch cable is too tight causing the clutch to slip or your kickstart quadrant is noy shimmed properly and has walked out of the chaincase cover amd is rubbing on your clutch which would cause it to slip.

First thing I'd do is just unhook your clutch cable from the clutch arm and see if that fixes it. If that doesn't do it then you'll need to open the chaincase again and figure out why your clutch is slipping when you kick it.

disagree that its "100% clutch related"- it may be but my monies on the front sprocket. You need to whip off the cover and have a look

Chris

[holty]

clutch was my first thought, or front sprocket bolt has come loose.

[Scooterdude]

I bet the clutch retaining circlip has pinged off. If it has you will need to replace the clutch basket as the grooves will have worn and simply replacing the circlip will mean it will happen again.

[joespeed]

If you have no compression when you kick it, that is 100% clutch related. The flywheel is only indicating that the kicker is not turning the crank over.

I'd guess either your clutch cable is too tight causing the clutch to slip or your kickstart quadrant is noy shimmed properly and has walked out of the chaincase cover amd is rubbing on your clutch which would cause it to slip.

First thing I'd do is just unhook your clutch cable from the clutch arm and see if that fixes it. If that doesn't do it then you'll need to open the chaincase again and figure out why your clutch is slipping when you kick it.

no compression usually means someone has nicked the sparkplug or there is a hole in the piston,
i guess that you have not tightened the front sprocket and given it a 'ding' with the hammer to check if it has located correctly!
take the crank case side off and check you have it right,all other things that have been mentioned can also be checked!

[george4422]

All, thank you so much for the replies and suggestions.
Prior to taking the side casing off, I unhooked the clutch cable, and sure enough, it started first time! So, I had a look inside and the front sprocket bolt was tight (impact wrench was used) and the circlip was still in place! I then dissassembled the clutch and everything looked fine... The side casing was put back on, and the clutch cable was lengthened a tiny bit via the trunnnion, and all seems good. Fingeres crossed! Thanks again.