i picked up a 77 gransport about a month ago, wasnt running at the time.
1977 (gransport 25mph version)
NOI single speed engine
14.12(original was 14.9) with curved intake
not sure what cylinder, crowned piston head
so far it has had new plug/boot/wire, replaced 14.9 with 14.12, cleaned points, clutch bushings put in (if thats what you call the little rubbers that go on the 6 nips), filled with the 13.5oz nondetergent 30wt., fresh gas, new petcock and fuel line, and cleaned out the exhaust. also did some cosmetic stuff like new pedal crank and a lot of scrubbing to remove surface rust.
where i am at now the bike will start around the 3rd kick, however it doesnt want to idle (though i can make it idle with way too much tension in the throttle cable). also it has remarkably low power at all revs. i can sit with my feet on the ground and go full throttle and it doesnt fight me much. wont really go up hills either. dont know how fast its going since speedo drive is broken (let me know if you want to sell me one) but it will slowly reach moderate speed on flats but nothing near the 25 its rated for.
Also the lights will flicker when its running. maybe need stator replaced?
the one thing that the bike is missing mechanically is a head gasket. this is causing a massive air leak such that when i spray with carb cleaner it dies instantly. obviously this is bad but would that cause such poor performance? is it low compression? (and how do i test compression?) would new piston rings also help? (didnt check ring gap) i know sometimes bikes run better w/o the head gasket but this is my first garelli.
My second suspision is the clutch. i took it apart and it seems perfectly fine. the rubber is firm and black like it should be, not swolen as far as i can tell. when i got it the little rubber bushings were completely gone (yet no debris from them falling apart was present) so i made some out of clear fuel line following the dimensions on the wiki page. is the clutch slipping? (im not good with clutches) and if so will sanding the rubber puck help?
Please let me know what you think and any suggestions from the garelli gurus would be lovely! Thanks!