Looking for some help, with my 08 xl1200 l. The motor has been torn down several times in the past year for different reasons and just recently I started getting a popping sound (like a backfire) and exhaust coming from the FRONT end. I'm confident that it is a basic back for and I messed up the exhaust gasket when I put it in, but what would cause it and how do I fix it? Also how bad is it for the bike? I've read stuff about "carb fart" and that seems to be the same thing but this is fuel injected

 

You describe an exhaust leak. You said you messed up the gasket? There's your clue. I'd install a new gasket and re-install the pipe. Exhaust leaks are something you want to fix, I've heard it can cause problems (warped valves?) but no first hand experience on that. I have changed lots of exhaust gaskets, having owned many VWs in the past.

Carb farts are a sudden lean condition in the carb itself. Not an exhaust leak.

John

 

When a FI bike is shut down, there is always a charge left in the intake. (Throttle by electrical wire helped some, especially when deceleration and throttle is snapped shut.)

However depending on heat in motor and where motor stops, it can get a pop in exhaust. It's very little fuel and a lot of air, so it pops rather then just burns smoothly.
Mine does it occasionally. Sometimes out the intake, mostly out exhaust. Sometimes, loud.
Mine did it one night after 12 AM.There had been a bar fight and two police where on the corner. When bike went bang, one spun around. His buddy was rolling with laughter. I was just glad they where in a good mood.
If you have a header leak, you can fill and see it with a piece of paper taped to a stick.

 

When it "pops" I see the exhaust come from the front, i believe it to be from around the exhaust flange. I am changing the pipes next month after Christmas so I'm not too worried about the exhaust and exhaust gasket. I'll change the gaskets when I change the pipes. But the pop concerns me. I'm not sure how to fix it being fuel injected. And it only happens on startup after it has been sitting for a few hours

 

I have to put a tuner on it after changing the pipes will that adjust it

 

The tin man has spoken.