I spent part of today running through some of the above.
Gas cap is vented type
Manifold bolts are tight (checked them).
Pulled top of carb to look for trash and verify jet size per manual. All OK.
Fuel lines look orginial and in correct place.
I have one of the newer timing lights, so I'll check operation of vacuum advance this weekend.
One thing I want to do is change plug brands. I've had bad luck with ACDelco on a 250 inline several years ago. Went to NGK and problem was solved. Heck, there isn't much left to check.
Thanks.
