Carb Trouble

[RichM1983]

I have a problem with my carb.

When I turn the gas on the fuel just runs right through it and out the hoses. I took it apart and cleaned it really well, checked the floats to the best of my knowledge they looked good. The needle that the float pushed into the hole to stop the fuel flow looked good and the hole looked good as well. The carb has been sitting a while not being used so I cleaned it really well. The bowl was leaking as well so I used some silicone to seal that up but now its leaking from the hoses. The carb looks brand new after a cleaning and the floats look fine. The only thing i didnt check was to make sure the floats would actually float because I know they can bust with age but they looked fine.

Any other ideas?

[Aceman]

It's one of these three things:

1. Floats are sinking.
2. Float needle not sealing.
3. Float height is incorrect.

Sounds like you eliminated #2, but I'm betting it's #3. If this is a Keihin carb, float height is around 16-17mm if I remember right. Measure from the carb base to the line on the side of the floats. When it's set right that line is about parallel with the base of the carb. The tang on the float should just barely be touching the spring loaded plunger on the float needle at this point.

I wouldn't consider silicone a quality repair either when used on parts containing gas. Best to get a new bowl o-ring.

[RichM1983]

Originally posted by Aceman
It's one of these three things:

1. Floats are sinking.
2. Float needle not sealing.
3. Float height is incorrect.

Sounds like you eliminated #2, but I'm betting it's #3. If this is a Keihin carb, float height is around 16-17mm if I remember right. Measure from the carb base to the line on the side of the floats. When it's set right that line is about parallel with the base of the carb. The tang on the float should just barely be touching the spring loaded plunger on the float needle at this point.

I wouldn't consider silicone a quality repair either when used on parts containing gas. Best to get a new bowl o-ring.

I'm prety sure the needle is sealing. The only way I can really determine that was by pushing the floats closed and blowing through the gas line. When I did this it would definately not let me blow air through so theres no way it could be leaking fast enough to let gas go through fast enough to run out the lines so fast its like theres pressure behind it.

I do need to check to see if the floats are actually floating but I looked them over and didnt see any holes or cracks when I put them in and it was fine. The only thing I didnt do was place them in gas to determine if they would float.

As far as adjusting the floats I really didnt know how to do it. So what I did was blew through the gas line as I pushed the floats up and it would shut the hole off so that air wouldnt go through before the floats hit the on the carb. So I assumed if it was shutting off flow before the floats hit the carb that the level of the floats must be right.

Does any of this make sense? or sound like its correct?

And just to be sure this is the stock Keihin carb.

[cdrookie]

float needs to shut off way before they hit the carb. check it just like aceman described.

[Aceman]

Originally posted by RichM1983
As far as adjusting the floats I really didnt know how to do it. So what I did was blew through the gas line as I pushed the floats up and it would shut the hole off so that air wouldnt go through before the floats hit the on the carb. So I assumed if it was shutting off flow before the floats hit the carb that the level of the floats must be right.

To adjust the float height, bend the tang that contacts the float needle. Use a ruler and make sure you're around 16-17mm from base to float line.

[RichM1983]

Alright I'll check the float level and make sure they still float. Thanks for the help.