<VV> Assistance with a carb problem

[Bob Gilbert]

Hi,

 

I haven't had a normally aspirated 110 for at least 15 years so my
diagnostic skills are a little rusty and I need some help with the
following.

 

It's a 68 110 with late carbs with vent valves at the base so they are at
least 64 or later (from memory)

 

I kitted both carbs, new everything except floats and main jet, set them up
with a 1 1/8 float height and set everything else as per spec. I also added
throttle shaft seals just for good measure

 

The engine starts easily and revs fine but has a rough idle.  While at idle,
perhaps once or twice per minute and seemingly at random I get a back fire -
more like a loud "phut" through the muffler.

 

A look down the RH carb shows the venture cluster dribbling gas which I'm
fairly certain is the source of rough idle and the backfires. There is no
such dribbling out of the other carb 

 

I've checked the float level and it is definitely at 1 1/8 . Should it be
lower? Or is it something else?

 

Thanks,

Bob