KX Riders

Maintenance & Technical => KX500 Original => Topic started by: dmg on December 27, 2011, 02:35:20 PM

Title: Window Piston Jetting?
Post by: dmg on December 27, 2011, 02:35:20 PM
Hi All,

Seeing that there are a few piston threads right now, I hope someone has some direction to give along these lines.

A year ago I replaced my stock '92 piston with a Wiseco Window piston. At the same time I threw in a V-Force Reed cage. I have not been able to get good jetting since. The middle to upper range is flat on power. What jetting changes should I expect to make with these mods?

I usually run around 2000 feet, and 60-80 degrees. I currently have in a 58, 168, and 3rd clip.

Thanks,

Darin
Title: Re: Window Piston Jetting?
Post by: alward25 on December 28, 2011, 05:21:20 AM
Have you tried opening your air box vents.  I was having the same problem with the same jetting.  Opened the vents and it went away.   500's need air!!!!!
I should add that i think the problem is that I have a battery and reg/rec in the air box and is most likely restricting the airflow some.
Title: Re: Window Piston Jetting?
Post by: Foxx4Beaver on December 28, 2011, 05:57:51 AM
You need to check your plug after a WOT run,and determine if you're too rich or too lean first(if you have'nt already),
You say it's "flat" middle through top....which could also be worth checking your KIPS to be sure they're timed correctly.

Foxx
Title: Re: Window Piston Jetting?
Post by: flyingfitz on February 01, 2012, 01:27:43 AM
52 pilot, 3rd clip on n82r, 168 main, air screw in from 1 1/2 to eliminate surge. Works good at 600 ft.

Kips bolt mod, uni filter, airbox ports closed, VForce 2 no spacer.  94 pump gas and Bel Ray H1R at 50:1. Plug gapped to the middle of the suggested range, I think it is 22 or 24 on a B8ES.

Starts right up, never fouls a plug, revs to the top of the pipe.  A touch soft in the mid range response for the woods.  
Title: Re: Window Piston Jetting?
Post by: flyingfitz on February 01, 2012, 03:12:42 AM
Re-pack the silencer before you jet.  Old/clogged packing can have the effect you are describing.  Don't ask me how I know!
Title: Re: Window Piston Jetting?
Post by: kwakman on February 12, 2012, 12:08:48 PM
what pipe you running? fmf gnarly (020055) murders top end...