Im looking for some cheap ways to increase an otherwise stock hp. It has a LRD exaust with matching jets and KN filter. Is there anything else I can do that is fairly cheap?

 

You can do the Sparks Timing Advance Key (about $20) and drop a tooth on the front (about $20) for some added bottom end pull. Both very inexpensive and make a very noticeable difference.

 

Thanks that will help

 

Hey spray?
Could you send me a link to the arrester, im not familiar with those.

 

If you drop a tooth on the front sprocket you may not like the lost topend, if so then drop one tooth on back too, to help regain some of your lost topend but not reducing your gained lowend much.

 

I found it, at http://www.atvriders.com/articles/timingkey400ex.html

Thanks Ill try it

 

thats helpful, so overall a tooth down on front and rear will increase response?

 

That is correct. Let's say your sprockets are 13/38 front & rear. This is a ratio of 2.92 to 1. If you drop to a 12 in front, your ratio will be 3.16 to 1. You want something in between those ratios so if you go to a 12/37 you will have a 3.08 to 1. Or if you leave the front at 13 and change the rear to a 39, you'll have 3.00 to 1. See, when you change the front you have a much bigger effect on the total ratio than when you change the rear. Going from a 13 to a 12 is an 8% change of that sprocket, but going from a 38 to a 39 in back is only about a 2.5% change.