Scooterotica

Hey all,

Got a 1965 Li150 that I installed a PHBL carb on. I've put like 3k miles on this thing and it runs fantastic.

The problem I am having is, occasionally the kick starter doesn't seem to draw fuel into the combustion chamber. I kick and kick and kick and nothing. It's almost like a vacuum seal, and kicking it doesn't turn the bike over enough. If I pull the spark plug, kicking it spins the engine very freely and draws enough fuel in, and then it will start with one kick. Also starts easily bumping it down a hill.

I can't predict when this will happen, or replicate it. Once the bike is warmed up, this does not occur. But it can occur after the bike sites for an hour or so.

It's a f-ing pain in the ass and nothing I've tried will solve it.

Any ideas?

My first thought is a slipping clutch.

Daggs wrote: ↑Tue Jun 06, 2023 8:10 am My first thought is a slipping clutch.

Interesting. I don’t know how the internals work but does the kickstarter engage the clutch? I’ll say it never slips when I’m riding, Including when I’m blasting up a hill at high rpm.

The kickstarter turns the gearbox which turns the clutch the chain transfers the movement to the crankshaft.
You describe the fault as being intermittent. These are always the most difficult to diagnose.
I'm sticking with the clutch theory. Possibly weakened or broken springs. Maybe worn out corks.
The only other thought I have is the kickstarter is not engaging with first gear. But you say with the plug out it turns the engine fine. Low resistance , no clutch slip.
So there you have my thoughts. Take 'em or leave 'em.

One more thing. Next time it happens, operate the clutch several times. Just in case the plates are sticking in the basket.