Hello all. I have an 89 883 with a keihin cv carb (pre accel pump) I’ve had the bike a fair few years however it’s been off the road for some time. I re built the carb, had a hole in the diaphragm on top of the slide and also a hole in my float. Part of my kit was a four sided float needle, the old one had just 3.

checking hd shows this is the updated part so cool I went and installed it, I set the float height to .730 (18.54mm) with the carb upside down on my bench.

plumbed it all back in turned the fuel on and within seconds the bowl overflowed. Took it off and increased beyond 18.54mm it slowed and after trial and error I’ve almost stopped it completely.

am I right to need to set this height above the .730 in the book. It leaks so much if I don’t to the point excess fuel is coming out of the jet holes when the engine is running, I rode a few miles and my rear plug was jet black with the rich mixture running into the chamber.

im really lost on this one I’ve had it apart and cleaned and re built it several times always ending up in the same situation, I even tried the old float needle and got the same result. Any ideas from the gurus here?
I may have made a ver simple mistake but it’s driving me mad.

thanks

 

might need to research the net for the carb instructions.
some of these require the carb to be at a certain angle when checking/setting float height. mine requires 15>20* angle of the dangle. make sure you are using the right measuring points.

 

Yep. The book gives the .730 spec but with the newer float valves, the round floats have to be measured at 15-20 degrees like the '92 and up square floats.

All the bowls had an overflow/drain until they went to a vacuum petcock so you can use the drain and a clear tube to do float level check and verify it's where you want it. And there are other things that can cause over fuel or flooding conditions.

 

i see that makes sense. Would having the carb at an angle make much difference to doing it inverted? I’ll check it in the morning. Thanks

 

Yes definitely!
Even with the (much) lighter round floats in the pre- '92 CVs, the difference in measuring between upside down and @ 15-20 degrees will usually be .080 - .110

It's not complicated but is a bit tedious, so just take your time. Once it's set, unless you have to change the valve again (shouldn't ever need to) you'll never have to adjust it again.

If you don't have an angle finder, at a hardware store pickup a pack of wood door shims. They're cheap like $2.00 and most are 1/4" thick on one end. Stack 8 together and that will give you approx. 15 - 18 degrees and a surface to rest it on while measuring.

I shoot for .715 - .720 and that puts the fuel level even with the seam between the body and bowl which is optimum, as checked with a clear tube on the drain.

 

awesome. I’ll probably make myself a jig out of wood. Always useful to keep. I’ve been setting it inverted. I’m hoping that is my issue

 

is there much more to the procedure? My manual is 88-90 that’s why I don’t have this but relating to the new needle.

 

The angle makes the float "hang" differently.
A jig is a must for proper measurement.
Harley makes everything a project.
Don't get me started on bolt sizes, lengths and thread cuts.

 

No, that's about it. I took those pics from a 91-92 manual which was the transition date between valve types.

If you take your time and measure correctly, it's a very accurate method.

The FSM does not show or explain the clear tube method of checking and is good for fine tune on multiple carb bikes or just for a quick check before pulling the carb if you're working on a problem child. Plus, not all HD CVs have a drain.

 

yeah mine is overflow not drain so wouldn’t work