need jetting help

[southbeach14]

i have a Dr.D slip on and a um air box. and a dynojet ket , at high rpms its beaking up. help.

[gizmocor]

If it is only breaking up at high RPM it is probaby to rich. You need to find out if it is doing it at full, half throttle, or both and lean out those circuit as needed.

[southbeach14]

is the best way to cover air box and see what happens?

[gizmocor]

Not really......Ride the quad at a slow speed and shift the motor up into like 3rd. (which is really to high a gear for how fast your going). Push the throttle to half and let the motor pull and wind out. Do the same setup again but push the throttle to full instead of half. If the motor breaks in the lower RPM's it is usually to lean and if it breaks up in the top RPM's it is usually rich. If your problem was only with the half throttle position change the needle clip, if it is at the full throttle position change the main jet.

Hope this helps

[southbeach14]

thanks i will try it

[seven]

Get rid of the dyno jet kit, Put in a 175 main,172 with stock filter. 45 pilot and 2 1/2 turns out on the mixture screw. This is at 2500ft

[southbeach14]

i have mine with a k&n and a um air box, and i'm at 1500

[660bigdaddy]

mark, did you call dyno jet yet? what size is compareable to a 172 ?

[southbeach14]

Originally posted by 660bigdaddy
mark, did you call dyno jet yet? what size is compareable to a 172 ?

they were no help at all. they said they have no idea because i have a um air box and they didn't test with one. i'm going to buy a gytr jet kit or a jd kit what do you think??? did you see your racing pictures from ohio??? you have two

[660bigdaddy]

don't waste your money with anymore jet kits. i would go buy the jets they used in the shoot out and try that. or try the duct tape trick in thier directions. let me know if you need help. what ever you do, don't take it to the dealership.... it will cost you an arm and a leg.