I own a 2005 trx 450r. i have a comlete big gun race series exhaust system, and an open air box with a k&n air filter. what should i do jetting wise, can i just change the main jet...or what?

 

<div class="FTQUOTE"><begin quote>Originally posted by: ivotaw12

I own a 2005 trx 450r. i have a comlete big gun race series exhaust system, and an open air box with a k&n air filter. what should i do jetting wise, can i just change the main jet...or what?</end quote></div>


It depends on your altitude and a few other things. What are you jetted at now?

 

You'll need to not only change the main but also the pilot jet and drop the clip on the needle.
Big Gun should have a customer service # that you can call and get a good starting point for your jetting, but a lot will depend on where you ride.

 

i went online and big gun had specs but none for my quad. i always ride on the dunes at the beach, so i have to be right at sea level

 

o and my jetting is still stock, i havent ridden it except up and down the street. it back fires all over the place.

 

Rejet!!!!!!!!!!!
Do not ride it with the stock jetting with the pipe and airbox mods!!!! You are very lean!!!!!
Start off by adding a 180 main jet, and I think I went to a 42 pilot jet and drop the clip on the needle to the last (bottom) setting.
You may also need to back your air/fuel mixture screw out 1/2 to 1 full turn.

 

<div class="FTQUOTE"><begin quote>Originally posted by: Red400EXRod

Rejet!!!!!!!!!!!

Do not ride it with the stock jetting with the pipe and airbox mods!!!! You are very lean!!!!!

Start off by adding a 180 main jet, and I think I went to a 42 pilot jet and drop the clip on the needle to the last (bottom) setting.

You may also need to back your air/fuel mixture screw out 1/2 to 1 full turn.</end quote></div>


Quted for truth.

If you ride it with stock jetting and aftermarket parts you'll notice it runs worse, MUCH worse.