help reject or no reject after adding a slip on?

[mattstolte]

I have a all stock 05 400ex. So what I did was added a two brothers slip on exhaust, then took air box lid off and added a k an n air filter with outter wear cover. So once I did that I was expecting to take it to shop to get rejected. But it started right and ride it and stays running good so I'm wondering am I fine then I don't need to rejet? I'm wondering could I be doing any damage to the engine?

[DragonGunner]

Whats your elevation? I'm at 750 ft. here in Indiana and highly recommend you go up on the main to at least a 165-170. I run a 185 main open air box k&N, outerwear but also have it ported and high compression piston. If you run too much on the lean side for too long you can burn the rings, then the next thing is oil will start slipping past, then its smoking and then rebuild time….the closer you are to lean without being lean is good, also in the cold a little lean in summer will be really lean in winter. In winter I throw the lid with a few holes in it to rich in it up, cut down on air which makes it run richer(cold air is denser). That way I never have to change out jets. I prefer to be a little towards richer than lean. Keep a check on your spark plug, every few hours, should be light tan brown…..blacker is too rich and white is way lean.