Well all this tuning talk got me a little curious and I went and modified my air box and got a k&n for a Bear Tracker. Looks awesome but now it wont run for *&%$ I guess this is the point where I need to have my carb re-jetted right? Here as question, I will have to take my atv to a dealer to have this done sense I have no idea how to do it my self, how will they know the proper size jets to use? I think I should wait until I put on the new muffler to take it in. Anyone know a company that makes reeds for a bear tracker? I guess I will just do this all at once.

 

A bear tracker does not have reeds..it has valves...so forget that part.
As far as the jetting goes....A good mechanic will know which way to go with the jets by just listening to the engine and doing a few different checks. Most likely if you opened your airbox, you have increased air flow. In return you must also increase fuel flow or you will be running lean. (I'm guessing the machine is hesitating and skipping right now) You may be able to fix this by adjusting the air screw on your carb. or increasing jet sizes accordingly.

As far as a pipe goes...since your going to be increasing flow into the engine....it could only help to decrease back pressure out of the engine. Any aftermarket pipe will accomplish this. You will feel the difference...but it will most likely need jetting again. I would do it all at once if you can.

...Though you may feel enough of a gain with just the open airbox. Maybe someone who actually owns a beartracker can tell you.

 

Thanks for the info.

Yea she is pissed past half throttle dies out. FMF makes two mufflers the Powerline and the MegaMax for my ATV, How loud is the MegaMax? Its cheaper but I don't want my BT to be real loud.

 

I'm not sure on any of those pipes you mentioned...each will give you a gain for sure. But no idea how loud they are.

 

Thanks again, I got an email in to FMF to see if they can give me an idea on the jetting. I called my mechanic and he said that he could do the jetting job for me and if I got some info from FMF is would make it easier but he said he would figure it out if not. I think I can install the pipe myself that way all he will have to do is the jetting. I installed the K&N and drilled 1" holes in the top of the air box cover (about 6 of them). I have no idea if this was the proper way to do it but I am having fun tinkering with it.

 

You should get the whitebrothers(?) vents for when you drill your airbox, if you dont water can get in there, and make a mess.

 

DynoJet has been emailing be back and forth helping me out On what kit and what additional main jets to get. I had to call FMF to and some info from them, They tell me on my ATV just the pipe will not require re-jetting but removing nearly 50% of the material from the air box lid will LOL.

Thanks for the water tip, I don't do much mud and even less water but can never be too careful.