Rebuild carbs, new boots, new o-rings, vacuum leak

[Guest]

!!!

Just venting, I guess, since I already found the problem. But I have a '79 and a '78. I put new boots and head o-rings on the '79 two weeks ago, then I bought the '78 and transferred them yesterday. I disassembled the '78s carbs, soaked them overnight, blew out all of the passages, and put in new o-rings and bowl gaskets.

It fired right up! That's a good sign.

But then I tried synching it. To get anywhere close, #2 had to be turned in so far that it would lift the other three slides, and the other three had to be backed out to maximum adjustment.

I sprayed WD-40 at the carb boot to head mating surface on the #2 cylinder, and the engine bogged. I did it again, and the engine bogged again. I tightened up my vacuum fitting and tried switching two of the lines, no dice.

Apparently I was optimistic thinking that o-rings that were installed 2 weeks ago for the first time would seal up okay.

All o-rings from cycleorings.

*sigh* Now I have to wait for new o-rings.

-Matt

[eil]

Weird, haven't heard of new o-rings failing this quickly. Have you removed the manifold to see if the o-ring got pinched or something? Any chance the manifold is bent or some debris got in and is messing up the seal?

[lemonshindig]

Guess what, the o-ring fell out of the boot groove and dropped on the floor when I was transferring it from one bike to the other!

I cleaned it off, put it back in, and she's all synced and colortuned up!

[OldVet66]

That's exactly why I fill the grooves with dielectric grease, press in the O-rings and wipe off the excess. You will never have one fall out or get pinched if you do.