do you have to rejet with spark arrestor removed?

 

Please help me and mudmuster out here. When my warranty is out I am going to take the spark arrestor out of the stock pipe I think. Just by looking at the size difference of the holes with the arrestor removed it would seem like it would allow a lot more flow than when the arrestor is in there. Do you need to rejet and if you don't rejet will this cause a lean condition and increased cylinder temperature therefore destroying an engine. I don't have to take the arrestor out but it is quite the sleath machine with it in there. Chet

 

I am no expert on motorcycles, but I would think if the only mod you are doing is removing the stock spark arrestor you would not need to rejet. It seems to me that by doing this you are not increasing flow very much, now if you start drilling holes in the airbox and any other type mods to the airbox, I would say that rejetting would be necessary.

The best thing to do would be to pull the arrestor out and then put a new plug in and read the new plug after a little riding.

That would give you the best indicator.

Hope that helps a little
Paul

 

Yamaha jets the raptor on the lean side to meet epa regs. If you alter the muffler (and remv the baffles from inside the airbox snorkle, as most folks do), the engine will breathe better, but will be too lean and prob hesitate in the low rpms when you gas it.

A k and n jet kit solves the prob and significantly raises the hp.

 

Actually, it depends where (actually, what elevation) you are at and if your Yamaha dealer has jetted your Raptor for the altitude. Mine was on the rich side when I got it so for me it wasn't a problem. It is a hit and miss. Might as well by the K&N jet kit, or get a Motion-Pro Pro-Flow kit with an exhaust system, rejet, and ride. A properly jetted Raptor with the Pro-Flow kit and aftermarket exhuast (I have a CT Racing system) is how they should have come stock. Simply no comparison... none at all.

 

I am not sure of are exact level maybe 200 to 500 feet above sea level. I hate to start messing with my carbs when right now it really runs good or at least it seems to run good with what I had to compare it with and thats my former 99 300EX. I might try the plug test. Chet

 

shouldn't have to rejet, but check the plug to be sure.