I missed if you checked the float height. Wouldn't a leaking slide diaphragm do the same thing as described? Is that slide drilled out? When I was lean it would run out of juice but never bog.

 

I'll check with my buddy that rebuilt the carb regarding the float height. Would that explain it "running out of fuel" at aboit 4,000rpm in 5th?

 

So just to clarify, with stealth air filter and open pipes, a 185 jet should be sufficient? Or should I go larger?

Thanks everyone

 

I would want to know what needle is in the carb. I had an 04 Sportster with a carb. What really woke it up was changing the stock needle to an old N65C needle. They are tapered differently than stock. The jets did not make as big a difference as the needle change. Just my 2 cents....

 

The open pipes are probably hurting your performance more than anything. A little back-pressure would do a world of good. You can go up to a 205 main jet if you want to experiment. The needle only comes into play between 1/4 and 3/4 throttle. The main jet takes over after that.

 

Yes.....Especially it there is a restriction from the tank to the carb....

 

Are you sure you're at 4K rpms? Do you have a tach on that thing? Only reason I ask is you could be at 5k or so and out of steam and just not realize it.

 

Yes, it does have a tacho, it's 4,000 rpm. I took her out again yesterday, and like clockwork, 4th and 5th gear at 4,000rpm she coughs and dies (feels like when u run out of fuel), when I throttle back she starts to recover and then all is good.

 

So at full throttle it's clean at 3000 then right up to 4K it then coughs at 4K? I don't think that it's your carb then. What if you give it a little rear brake and hold it at 3500 WFO. Will it cough after a second or does it keep pulling hard until you let off on the brake and let it hit 4K.

 

Could be an ignition advance issue, clogged fuel cap vent, but I still suspect the carburetor. Take it down the road and cruise at around 70 for 5 minutes. Hit the kill switch and pull in the clutch and coast to the side of the road and remove the spark plugs. Take a picture of them and post them here. Find a safe place to do this and wear gloves! Even though it sounds like a lean condition, a very rich condition will correct itself when you feather the throttle like yuou are doing in 4th, 5th gear. I had that going on in 2nd, 3rd gear and it turned out to be an incorrect midrange needle jet. Read this page also:
http://cv-performance.com/harley-cv-...-tuning-issues