This last weekend I went out to a nice place in far east Oklahoma to ride with some friends. We were camped out off of a logging road so any time we went to ride or came back from riding, we were able to REALLY open the quads up on a hard packed and smooth dirt road.

My Ozark is modded with a TwinAir filter, DynoJet Stage 2 jet kit, and the spark arrestor has been removed.

So on a long straight, it felt like my Ozark was hitting a rev limiter of some sorts in 5th gear while going down a slight hill. The quad would studder then run smooth, then studder again till I slowed down a bit. I'm pretty sure this was a rev limiter, but I just want to make sure.

I've checked the spark plug right after this happened to see if it was running lean at all. Nope. It was DARK brown, almost black. So if anything, it's running a bit rich. It also would backfire out the tail pipe REALLY loud as soon as I let off the gas right after a long period of full throttle. Could this be caused by it running a bit rich?


I'm having one problem as well that might be related to it running a bit on the rich side. When crawling over some big and VERY rough rocks, the quad spits and sputters when it bounces around. As soon as I get to smooth riding again, all is well.


Now, on the jet kit, I had to go one size bigger on the main jet and one notch richer on the needle than recomended for my mods for the quad to run right. Anyone have any recomendations to fix these problems? Maybe get a pipe for it to lean it out just a bit?

 

I can't help you much with the spitting and spuddering, but if you are backfiring PUT THE SPARK ARRESTER BACK IN!!!!!! The last thing you need is setting your riding area on fire.

 

I agree, put the spark arrestor back in, it doesnt give you much more power, if any at all. That backfiring is normal, when you have the throtlle pinned for a while and let go, it will backfire. As for the rock problamo, I have no idea why its diong that.

 

The only time it backfires is if I'm riding on a VERY smooth surface at full throttle for an extended period of time. This means on a road surface. While riding on trails and on tight areas it never does it as the pipe never gets hot enough. The reason I removed it is the muffler was damaged and the outlet was slightly smashed closed when I went mudding. A friend of mine had to push me out of a mud hole and his quad hit my muffler outlet.

No biggie. I'm gonna go ahead and get a Pro Circuit pipe before too long anyway.