Just acquired low mileage (2100!) beauty but it sputters, backfires & snorts when it's cold. It gets a little better when it's warm, but still not right. Under throttle, it runs great, but backing off or running steady speed it will miss/spit/backfire etc. Pipes are stock Screamin Eagle & no known mods added. Dealership put it on dyno and said it's "normal". Put in new plugs with possibly some improvement. I'm concerned that it must have been in storage a long time and something suffered as a result. Appreciate any ideas.
Jack

 

Jack

The Revo engine after pipe and air cleaner changes typically buck and snort until at least 170 deg of water temp. I have an 05 SE and it did the same thing when i changed the pipes and air cleaner. The backfire,spitting and misfires points to a lean condition.

Did they add a fuel tuner with the SE pipes or reflash the ECM?

Another thing that will cause the backfire is if the muffler/pipes have slipped at there connections. Air will get drawn in thru the slits and cause the backfire. I had that problem when i changed the mufflers to Samsons. I ended up putting a stop on the slider support so the mufflers would not slide past the slits in the pipes. I couldn't get the clamps to tighten enough to prevent the slipping when they got hot. I didn't have any leaks the pipes and mufflers would just slide at the connection until the slots were exposed allowing air to get drawn into the pipes and result in the backfire.

Hopes this helps

Dennis

 

Thanks Dennis, for your input. Strangely, I now feel better that this problem has occurred for others. My SE doesn't seem to warm up very quickly and wondering if one can purchase thermostats with different temperature settings. I'm checking on the tuner situation & pipe connections you mentioned. Will advise!
Jack

 

sound like when whoever changed the pipes and air cleaner, didn't add more fuel and tune the motor. Popping, and snorting is a sign of it running lean. You should have a power commander or some type of tuning device added to the bike.,,,

 

Jack

The tstat doesn't have anything to do with how the engine warms up. The coolant bypasses the radiator until around 185. These engines typically run between 185-205 on highway. The fans will run on and off when in traffic depending on the ambient.

I let my bike warm up for about 5-10 minutes and then slowing ease it up to speed until it reaches 170-180 and then its pretty much ride it. I have the road glide fairing with all the instruments so that's how i know whats going on with the coolant temp.

I think you either dont have a tuner or the ECM reflash for the pipe and air cleaner change.

Dennis