How can I tell If???

[Anonymous]

How do I know that the needle valve seat and needle valve are seated properly? Carb 4 is too rich, and I am wondering if it is the needle valve/seat and float, or "just" an adjustment of the air fuel mixture.

John

[KEITH KRAUSE]

If the float needle valve is not seating well, the fuel in the bowl will rise and come out the floatbowl overflow tube.

[Anonymous]

Thanks, Keith.

So, as I have not noticed fuel puddling under the carbs, I should be able to assume that the needle valve seats properly? Now it is just a case of making sure the float height is adjusted properly, and the air/fuel mix?

Needless to say, I want to get this right, so I don't have a repeat of the oil/smoking deal.

John

[robinjo]

If you have your rack of carbs off the bike turn them upside down, take off the float bowls and blow into the fuel line, there should be no hissing/ bubbling sound what so ever but if there is you can identify what carb it is. There can be leaking through the valve and seat itself and between the seat body and carb if the red o-ring between the 2 isn't working properly any more or when they are not screwed in tight enough.

Good luck!

[Detman101]

Don't forget to check your float height.
My #2 carb is running rich and I found out yesterday that the float level is off a little.

Even after turning the mixture screw all the way in lightly and replacing the o-rings in the float valve seats on all 4 it was still running rich.

I always forget about the float levels affecting richness... :roll:

Dm of mD

[KEITH KRAUSE]

It sounds like your float valves are sealing but if you're going to check the float height, do the check as robinjo suggested. As he said, you could also get a leak through the float valve seat gasket or (some models) the o-ring.
A poor carb synch can result in your problem too. A loose jet will also. The carbs air passages must be clean.
If your carbs have rubber manifolds with o-rings, it's a good time to check/replace them too.
Does it look like the mixture screw has been moved? A cap still on it?