What does this mean!?!?

open up your exhaust pipe a little bit.

I thought the air screw only altered the fuel air mixture at idle?

After further testing, I think my carb might be malfunctioning. I think my float bowl is actually pushing my floats up, closing off fuel flow.

I can set the float to 0mm or level and it flows fine. Causing the bike to run rich. But if I adjust it at all, fuel will only flow without the bowl snugly tightened. Once I tighten the screws, fuel flow completely stops.

Too rich pilot mixture may be caused by improperly adjusted air screw which results in sooty spark plugs.
The air screw affects mixture throughout pilot circuit range, not just at idle rpm.

And just for grins, would assure the float mechanism isn't installed upside down.

Good Fortune!

treitz wrote: After further testing, I think my carb might be malfunctioning. I think my float bowl is actually pushing my floats up, closing off fuel flow.

I can set the float to 0mm or level and it flows fine. Causing the bike to run rich. But if I adjust it at all, fuel will only flow without the bowl snugly tightened. Once I tighten the screws, fuel flow completely stops.

Have you checked your bowl vent?

treitz wrote: After further testing, I think my carb might be malfunctioning. I think my float bowl is actually pushing my floats up, closing off fuel flow.

I can set the float to 0mm or level and it flows fine. Causing the bike to run rich. But if I adjust it at all, fuel will only flow without the bowl snugly tightened. Once I tighten the screws, fuel flow completely stops.

Is the float upside down in the float bowl? You can do that when reassembling some carbs.

I'm going to have to check when I get home. There is a good chance the float is actually in upside down. However I won't take credit for doing it because I bought the carb used, and have not flipped them while I have had it. I know that for sure.

big carb/little exhaust equals foul plugs=rich
little carb/big exhaust equals foul plugs=lean

donthaveakawman wrote: big carb/little exhaust equals foul plugs=rich
little carb/big exhaust equals foul plugs=lean

You might be right. I may need a more open exhaust.

Turns out my float actually was not upside down. I am having a hard time finding that 3mm sweet spot. But I did get adjusted leaner. So I'll run it tomorrow to see if its too lean. If it is, then I at least know that my float height is the culprit here.

Still rich. Still not confident my float height is set correctly, or that my float is operating correctly.

If you make a bunch of changes in the carb and it has no effect on the plugs, maybe it's not a carb problem?

Are you getting a healthy blue spark? And are they the right heat range plugs?
And is the timing correct? And? And? And?


Must be the meds :laugh: :laugh:

steell wrote: If you make a bunch of changes in the carb and it has no effect on the plugs, maybe it's not a carb problem?

Are you getting a healthy blue spark? And are they the right heat range plugs?
And is the timing correct? And? And? And?


Must be the meds :laugh: :laugh:

I did check the timing last weekend, and the spark looked strong. I can double check though.

I'm almost positive the carb just isn't working right. It's almost like the floats are hitting something so they wont move freely or something. I think I'm going to just take it to a shop and have them bench test it.