I have a 1999 Fatboy with Mikuni HSR42 carbs, it is running really rich, I adjusted the idle screw, but can't seem to get it too lean. I was told that I may need a rebuild kit if I can't get it too lean with adjusting the idle screw. It started to do this a few days ago and am fouling plugs, it seems like I can go down the road and burn off the fuel, but when I am idling around it is having problems. I put some sea foam in the tank and was told that the additive may cause it to run like crap for that tank and to run the tank out and see if it fixes it.This is the first Ihave had problems with it since I've owned the bike so I amassuming the jetting is correct because it was working perfect before. I have Andrews Cams, Hi 4 ignition installed too. If I do have to rebuild the carb, is it something I could do myself or do you suggest taking into a mechanic.

 

You may need a smaller pilot jet.

Would a dirty / clogged air filter contribute to that?

 

My friend had a Twinkie that's been fowling plugs regularly.

He's taken his bike to various shops trying to figure out why his HSR42 was fowling plugs and none of them could figure it out!

Can you believe that Harley-Davidson sells a chrome choke **** that goes over your existing **** and was leaving his enrichner hung open!

WHAT A DISASTER!!! HD TOTALLY SUCKS....

HOW CAN THEY SELL GARBAGE LIKE THAT???

Removed the stupid chrome **** and problem solved.

 

Aside from the Time Warp aspect of your post..

Just maybe HD sold that **** farkle for CV carbs NOT the aftermarket Mikuni ??

 

its compatible with both carbs so no difference.