Generally if you are only changing pipes, there is very little change in the airflow in the engine, however if you add a more free flowing exhaust and a high flow air filter then you have greatly increased the air flow and the standard system just isn't designed to compensate that much. It really only compensates for mixture when starting and then for altitude changes while riding. That much air flow difference is more than the factory settings can handle. Add a fuel manager like a power commander or other brand and download the correct map or have it dyno tuned. Mine was downloaded into the Power Commander and it runs like a bat, no popping on deceleration, and I get 48 MPG. Can't complain, but I did have to add the PC.

 

I changed pipes and went to the SE Breather, had the dealer do the Stage one download. The bike ran better, but, the stage one didn't do anything for the "nut roastin" heat. Went to another dealer and he said do the SERT with a Dyno tune. Did it, and all that engine heat is gone and the bike runs great. Best thing I've done to my bike!!! With the SERT if I want to "cam" it or punch it out ,all I do is take my SERT and after they make the mods, they make another dyno run, retune it and give me back my SERT with the new map!

WHY,THERE'S NOTHING TO IT,
A MERE CHILD COULD DO IT!!

 

Thanks for the good info guys!! Guess I'll pony up in the next week or so and get this done. WIll advise!!