So this all started on the highway at about 70 miles an hour. I didn't think much of it at the time but every once in a while the bike would pop or lurch and lose power. It rode fine around town but yesterday I was back on the highway and it started again. slowly at first but after a while I couldn't get any power above 2000 rpm. Today I pulled the air cleaner off and noticed that there were cracks in the tubes that come from the cylinders and slip in behind the air filter so I replaced those but it was no effect. I assume it's a leak somewhere because if I hold the choke it seems to run fine. Now at in town speeds it's missing and popping loudly. The bike is a carbureted 2002 fatboy. Anyone have and thoughts on what else it could be and/or how to check? Thanks.

 

Have you checked or replaced the cam tensioners ?

 

Pull both spark pugs and post a pic for the experts here too see.

 

You're describing the classic intake seal leak, at an idle use a can of brake clean with the little tube attached and give a couple small shots around the intake clamps on the heads. She drops out you found the leak.

 

Here are the spark plugs. The darker one was in the forward cylinder. I picked up a can of brakekleen but I'll have to wait till tomorrow to test the leaking, not enough light.

 

As for the cam tensioners I'll probably have to wait till next weekend... or till I learn how to do that lol

 

Any chance it could be my main jet is clogged?

 

Check for a intake leak before you chase your tail any further please. A tip from an old MC mechanic ALWAYS check the basic stuff FIRST before you start tearing into things, 9 out of 10 times it will be the common stuff.

 

Oh I am. I checked with brakleen and nothing, didn't even die a little. Tried again with some wd40 and even a little carb cleaner, no revving up. I did notice an odd fluttering noise though so I pulled the air cleaner off and took a short video. You all probably know if this is normal or not a lot better than I would. https://www.dropbox.com/s/08gnemrvvub357z/20160718_190825.mp4?dl=0

 

Not the dying but the weird flutter. Maybe a tear in the membrane?