1980 Vespa Grande starting issues

dkgt 314 /
This single post is part of a larger thread. Start from the top or view this post in context.

Hey all,

New to the forum and new to mopeds. Bought a 1980 grande a few months back, owner stated that it ran last year and had been sitting. Has ~3k miles on it.

Gas tank was in good shape but I flushed it anyways and made sure gas was flowing into the carb.

Cleaned the carb twice with carb cleaner and compressed air, including idle circuit. Held a flashlight up to confirm that the gap through jet and up into the needle is clear.

Compression tester shows ~150 pounds, can get it up to 200 if I keep pedaling. Of course it won't rise unless I let go of decomp lever, but once it is up to 150, 200, squeezing decomp again doesn't release the pressure. Is this supposed to happen?

It has spark when I pedal and hold it to the fins. I also tried a new spark plug, both have spark. No lights.

Plug smells like gas after I've tried pedaling.

Spraying carb cleaner or putting a little 50:1 premix directly into the plug hole, then replacing the plug/boot and pedaling does nothing.

Motor can sometimes be kind of difficult to turn by hand after I come back the next day. A little bit of blaster temporarily solves this. Also kind of hard to pedal but maybe that's normal for grandes?

Starter clutch stutters pretty frequently, I can always get it to engage and start turning the motor if I keep pedaling but maybe something I have to keep an eye on, or maybe related to the high compression number?

Choke changes nothing, throttle makes it make a deeper sound but still doesn't start. Trying to start with no air filter changes nothing.

This video is not me (from an old post with some guy and his Bravo) but similar to my situation. Anything that can be gleaned from the sound?:

Looking for any advice on next steps or things to look at, thank you!

This single post is part of a larger thread. Start from the top or view this post in context.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account