There are a few different types of breather bolts. If you don't have the right ones in, you'll create huge negative pressure on the motor because the crankcase can't breath. I know because this happened to me when I installed the touring heavy breather on my 08 SERK. After a short test drive the engine quit and smoke was pouring out of the breather and exhaust for a few seconds. I opened the oil cover, and negative pressure rushed in like the sound of a shaken pop can. I put in the right breather bolts (that did not come in the touring heavy breather kit) and the problem was solved but it wasn't a pleasant experience. I think my problem was that I had the dealer put on a Stage 1 kit first, and apparantly the breather bolts were different for that kit. I put my stock breather bolts back on and everything worked after that.