Topic: Video Diagnosis Help

[Venturous]

Some of you may have seen my thread on the CB750 hack rebuild. We got it
started yesterday.

At idle it has a mild popping. The bike continues to idle OK and when I throttle
it, I do not get any hesitation. Just seems to have a mild backfire at idle.

During the rebuild we rebuilt the carbs and also replaced the old points and
condensor with Dyna S electronic ignition and also put in new coils.

Anyway, I am wondering if you think this sounds like a carb adjustment
problem or the timing off?

[Johnny5]

Leaky carb/manifold boot? Try spraying some carb cleaner around the boots when it's running. See if the idles go higher.

Could be plugged slow jets too.

[Gordon]

Clean the spark plugs off, let it idle for a few minutes, and then pull them again to see if you can narrow the problem down to one cylinder.  Also, feel around the exhaust header ports while it's running to see if you can feel an exhaust leak. 

[Venturous]

I noticed all the popping was coming from one pipe. I adjusted the air mixture screw for that cylinder half a turn and Voila! Sounds pretty good now...

[heffay]

idle still sounds a bit rough... rougher than it did before actually (without the small backfiring)
have you balanced the carb bank?

[martino1972]

yeah,she sounds a bit out of sync..........