Bike has been running great for the past 650 miles or so and just the other day, it starting having this problem. Occasioanlly (usually at idle or low rpm) it sounds like its running on 3 cylinders. There is a strong smell of fuel coming out the exhaust. There is a lack of power from a stand-still accelerating to about 6k. I've read many threads about people with the same problem, but they are usually running lean.

Things I've checked/done:
- New plugs gapped to spec
- fuel pump is operating normal
- no kinked fuel hoses/vents
- no loose grounds that I can find

Bike has a K&N filter and a Two Bro's slip-on. Those two should lean it out if anything. That's why Im so confused.

Maybe a stuck float valve? Air valve? When I accelerate hard, it clears up and I can hear the cylinder come back in. After accelerating, I stop, get off the bike to smell the exhaust and it smells normal, but quickly gains the raw fuel smell and it stars sounding like a Subaru.

 

It's most likely a carb problem. The carb on one cylinder is flooding over.

Time to pull them apart and have a look inside. But before you take them off, determine which cylinder it is so you know where to start looking.

 

Thats what I was afraid of. I didnt have time to do work on it awhile back so I took it to a stealership to clean/sync the carbs. Paid like $350. Since its been running great until the other day, I bet debris got in the carbs. Going to replace my petcock filters and fuel filter while Im there.

 

I would suggest figuring out which cylinder it is before you tear them all of the carbs apart. Determine which cylinder it is and the pull the plug. You'll want to see what's happening, if its flooding the cylinder or if its not getting fuel. It will help you figure out what other things to look for while you're cleaning the carbs.

What's the inside of the gas tank look like? Is it rusty and gummed up? If so, you may want to consider a tank liner in conjunction with new filters and cleaning the carbs. If the tank is rusty, it will continue to cause these sort of issues. A new fuel filter will only act as a bandaid.


Good luck, keep us informed.