Carb balance won't go

[unfazed]

Update: switched carb bodies, no change. They have the parts from the carbs that worked ok. Diaphragm, valves. Anything other than the bare bones.

Also checked: sprayed around inlets and both sides of the carbs all cylinders with easy start to see if it races, it does not. Also tried with a water spray the other way. Tried on the spark plugs too. Float heights seem correct also.

It's 3 and 4 running hard even when the tickover is right down. I get 2.5k on the tickover with the adjuster not even touching, and the balance screw taking 1&2 right up. 3&4 still flying.

The butterflys are completely closed for 3&4 and it still does this. I thought maybe something to do with the choke, but I have changed them with changing the carbs.


I'm at an absolute loss as to what to go after.

I have come across this a few times and the reason I fund in the Fazer

1. The slide needle Nozzles had fallen out and the owner didn't notice it missing and/or had fitted the nozzle upsidedown. This allows fuel to be dragged up through  the main jet by engine vacuum.

2. The main jet O-ring was perished  and again allowed fuel to be dragged up through  the main jet by engine vacuum. (this you said was replaced by a Viton O-ring)

3. The blank jet in next to the main jet was not tightened full an fell out and again allowed fuel to be dragged up by engine vacuum.