Modern Vespa

Thanks everyone who's chimed in so far.

I've got a 65' Li150 and I just installed a new intake and PHBL carburetor. I had to pull the entire engine and remove the exhaust and all kinds of stuff to get this to come together. I did not do a leak down test but i carefully examined intake, exhaust, etc and do not believe I have any air leak, at least not significant ones.

Today I buttoned everything back up, ensured I have good strong spark and attempted to try and start it.

With a new spark plug it would NOT start. I had to push it down a hill and pop the clutch to get it going and it ran like total shit for a few minutes and then died.

I was provided by casa Lambretta with the jets that are supposed to get me started so I believe it should at least run. I don't know whats going on.

Any advice would be great.

Wow! Every PH carb I've installed idled beautifully out of the box. Are the stock jets still installed? Everything tight?

Very strange. Ya everything's pretty much stock. Casa Jon provided jets that were supposed to get me close. Everythings tightened down. Tried to examine for air leaks with the engine out the bike but only had my eyes and ears to do so. Seemed pretty good though. Compression is strong! Very bright spark! Not sure what's up. What should I do?

One thing I've never done on this bike is check the timing. It has a new stator and CDI but I dunno what kind. I thought timing in CDI bikes was set and forget.

Nope. Always gotta check timing sadly. If you have the tools, put the stator in the middle of the slot for starters. Should be within a few degrees of perfect.

After that, make sure the air/fuel screw is about a turn and a half out, needle middle clip, choke fully closed. Usually is enough to get it idling.

Can you help direct me to some resource for the timing? I have a piston stop and I even have the tool you screw in the head that gauges the mm btdc. I also have a strobe timing light. There's so much varying info online about timing it's hard to find the right thing.

Check your PMs