Draft Cycle Works

Friday, August 16, 2013

Carb Support for VM29 Smoothbores on a CB750

I made this support using some 3/8 aluminum round and a few screws. Its held in position by one of the top case screws. Well see if it works for the long haul.

The reason I need this support is because the aftermarket boots to asapt vm29s to a CB750 kind of suck. They are quite soft out of the package and get even softer as they go through a few heat cycles. They also have a tendency to leak, which is a potential cause of my continually shrinking main jet size. I've been chasing a rich conditio all the way down to 110s and on pulse type carbs, a leak at the intake boot will cause the engine to run rich. This counters the more common thought that a leak here woyld cause a lean condition. Something good to keep in mind.

Ill be doing a little leak checking in a bit.