[axelwik]

imported post

I had the same problem after rebuilding my GL1000 carbs. It went away after carefully balancing the carbs.

Other than that, it could be that compression is low or not the same on all cylinders. Since you just got it running, and it hasn't been on the roadverly long, run the crap out of it tohelp re-seat the rings. You might also want to run the engine for ten minutes with some of that kerosene-type motor flush stuff, then change the oil.

 

[axelwik]

imported post

Yep, I'd take care of all the tune-up issues and synch the carbs... That should take care of it.

Like Vic says, you could also check for vacuum leaks, but I'm sure you replaced all fiveof the vacuum hoses, replaced the runner-to-head O-rings, replaced the plenum gasket (if you split it), replaced the plenum-to-carb O-rings (if they were removed), and inspected the rubber boots between the carbs and runners.

If you did all the above and the problem persists, check compression. One or two cylinders much lower than the others can cause this.

If compression or vacuum leaksare not the cause, take the carbs off and re-check the float levels and condition of the floats. Somepeople even go so far as to weigh each float to make sure they are a good match. Float level on the GL1000 is critical. On the '75 to '77 it's 21mm (may be the same on your '78)-EXACTLY 21mm. Don't let this vary by more than a half millimeter. It's measured from the top of the ridge on the carb body that surrounds the bowl gasket, to the bottom of the float. This is with the float slightly pushing the float valve closed, but not enough pressure to compress the little spring-rod in the valve pin. Check both halves of the float. If they are uneven they can be bent slightly to line up.