2003 intruder 800 rear cylinder extremely rich at idle HELP

[Eklundcc]

Hey all,
So I bought this bike for cheap recently and have been working on getting it running right. It was completely dumping fuel out of both carbs, so I took them out, rebuilt them, and adjusted the floats. It is no longer dumping fuel, and is running pretty great off idle, but I cannot figure out why the rear cylinder is running extremely rich at idle. I can guarantee the pilot jet, main jet, and float levels are all correct (I’ve done them multiple times now with a quality rebuild kit). It is running so rich that turning the AF mixture screw completely clockwise still isn’t “lean” enough. Spark is strong, compression is great, it is definitely a fuel issue from what I can tell.

So, ruling out the pilot jet, main jet, and float level (sits ~1/4” below bowl mating surface), does anyone have any suggestions on what the issue might be?
It’s running so rich it’s almost misting fuel out of the exhaust pipe and fouling plugs.

Does the diaphragm have any effect on the idle circuit? I noticed the diaphragm “plunger” for lack of better word has had the air hole enlarged by the previous owner, what effect would that have/why do it?

[hillsy]

Are you checking the float height or the fuel level?

[Eklundcc]

Fuel level, sorry. I used a clear tube at the drain port to check the fuel level of the bowl. Sits about a 1/4” below the bowl mating surface

[Herb]

Have you checked to make sure the choke (enricher valve) is properly working? I had the front valve stick open and it did about the same thing you are talking about except it would foul the plug if I let it idle very long

[Eklundcc]

I did, and it seemed to be functioning fine with no kinks or anything. I may just temporarily completely remove the choke cable from the rear carb tomorrow and see if anything changes.

Do you have any idea why the diaphragm plunger (Sorry don’t know the correct term - the black piston thing that slides up and down) would have the small air hole drilled out and enlarged? I’m thinking the PO may have installed a jet kit or something and maybe that has something to do with it. But I replaced all the needles and jets back to factory spec.

Sorry I’m not well versed in carburetors, FI is much more my speed. Thank you for the help!

[hillsy]

I did, and it seemed to be functioning fine with no kinks or anything. I may just temporarily completely remove the choke cable from the rear carb tomorrow and see if anything changes.

Do you have any idea why the diaphragm plunger (Sorry don’t know the correct term - the black piston thing that slides up and down) would have the small air hole drilled out and enlarged? I’m thinking the PO may have installed a jet kit or something and maybe that has something to do with it. But I replaced all the needles and jets back to factory spec.

Sorry I’m not well versed in carburetors, FI is much more my speed. Thank you for the help!

A lot of aftermarket jetting kits will instruct to drill out the hole in the slide. This is to adjust the responsiveness of the slide for different taper needles.

[Eklundcc]

I did, and it seemed to be functioning fine with no kinks or anything. I may just temporarily completely remove the choke cable from the rear carb tomorrow and see if anything changes.

Do you have any idea why the diaphragm plunger (Sorry don’t know the correct term - the black piston thing that slides up and down) would have the small air hole drilled out and enlarged? I’m thinking the PO may have installed a jet kit or something and maybe that has something to do with it. But I replaced all the needles and jets back to factory spec.

Sorry I’m not well versed in carburetors, FI is much more my speed. Thank you for the help!

A lot of aftermarket jetting kits will instruct to drill out the hole in the slide. This is to adjust the responsiveness of the slide for different taper needles.

Would this have any effect on the idle circuit? If I look into the carb while it is idling I can see fuel coming out around the needle/main jet area