Modern Buddy

Had sat for a couple years. Petcock was seized up so replaced it. new fuel filter. cleaned carb and installed new spark plug but it will not idle. if throttle is held at least 50% it will stay running but as soon as i let off it dies. have already tried adjusting idle screw.

The idle jet or other carb passageways are not clean. You’ll need to try again.

Ultra-Sonic cleaner the jets.

Only two things will cause that on a buddy. Plugged carb, or low compression. A happy engine should be in the 130psi range, and below 115 they won't hold an idle at all. If the engine was seized....I'm thinking you might have a burnt up top end.

The petcock was seized, not the engine. The petcock being gummed up to the point of seizure points to clogged jets. If the jets have been removed and cleaned there may be air passages that are blocked. This sounds like it needs a soak in carb cleaner in an ultrasonic machine.

Thanks for the replies will be cleaning carb again this weekend.

checked compression only holds 60psi.

So...low. Any reason to expect the engine had seized? If not, It’s possible if it’s been sitting for a while that the rings are sticking and will free up after some run time, maybe with a double dose of oil in the fuel in addition to the injector oil. I like to use Marvel Mystery Oil for this in other engines but haven’t had to try it with a Buddy.

Also, is it a decent pressure gauge? Is it accurate elsewhere?

This is sort of in the “hopes and dreams” category though. Your best bet with 60psi it to take off the head and have a look around.