Setting Harley Carb Float Level

[trikes4ever]

I just finished adjusting the float level on a TC88b CV40 carb. I used the procedure in the HD manual - the best I could. Also consulted with my indy - who says he's always just eye-balled them and bent the tab until the valve closes with the float parallel to the bowl mating surface. I find the official HD procedure confusing and complicated at best. Tilt the carb 15-20 deg, measure the distance between the 'perimeter' of the float and the sealing surface, bend the tab until this distance is between .413 & .453 measured with a vernier caliper...

What I did in the end was to do my best with the HD procedure, and then verified by blowing very gently on the gas line (I keep the gas line attached to the carb when I remove it) with the carb in its normal upright position while gently raising the float with one finger until the float valve just closed. You can't use too much pressure as it's easy to force the valve open, and also must use very light pressure while raising the float as there's a substantial lever arm. Doing this I confirmed that the valve just closed when the float was parallel to the bowl sealing surface.

Seems to me that what I did to confirm might be an easier and more straightforward way of setting the float level from scratch.

Would appreciate any comments by the carb experts out there.

 

[1550vt]

The dealers (and good Indy's) should have a jig to set the carb on to obtain the proper angle. You could make one out of a block of wood. OR...do it the way you did. If you set it too high it will run rich and may also leak out the overflow tube. Too low....and you will get a lean condition that will usually manifest itself as a pop in the carb, which will rupture the diaphragm if you let it go-on long enough. If it is set way too low...you can actually empty the bowl running at full-throttle and it will cut-out.

I'd just read the plugs and keep a watch on my fuel mileage. Ridiculously high mileage is not necessarily a good thing and running too rich will foul the plugs. Just get them that beautiful tan color and you will be fine.

It's a dance between float-level and jet sizing. The best way is to set the float "by-the-book" and then you can diddle with the other fuel circuits with jetting.

I have played with float-levels the same way you have....just keep a close watch on your plugs and fuel mileage until you are satisfied all is well.

NO...I do not consider myself a carb expert, but I have played with more than one.

 

[Ozarkryder]

I made a jig out of a block of wood, and a float gauge from an old credit card.
Measured upfrom a side to the low measurement, made a step and measured up to the high float leavel and made another step. Easier for me to set the float level with a gauge than with the caliper.

As an aside, the old way of setting the float with the carb flat was much easier. Seems the MoFoCo changed the spring in the inlet needle. This is even for older carbs, such as my '90,which is the first Big Twin with the CV.