Jetting?

[spliffy]

I Have A 88 250x & On Full Wide Open Throttle It Hesitates & sputters , If I Take The Air Box Cover Off It Revs Up & Does Not Sputter At All & Sounds Great , But That Is Way To Much Air , I Have Drilled Holes In The Top Of The Box , But I Know That Is Not The Solution (Quick fix basically) , I Know The Main Jet Has To Be Changed , But I Dont Know If I Go Bigger Or If I Go Smaller , Right Now I Have A 125 Main Jet In It & Its Starved For Air , So That Tells Me The Air/Fuel Ratio Is Wrong So Do I Need A Bigger Jet For More Gas Or A Smaller Jet For Less Gas & Therefor Less Air Mix? Im Confused , Any Help Would Be Great. Thanks :huh

[Wheelie]

Either run with airbox lid off, or step down one size on the main jet. Your quad is running too rich with the airbox lid on.

[spliffy]

I should Have Mentioned that My Plug Is A Light Brown/Borderline White Already.... doesn't that mean its lean as it is?

if your plug is that color...you are lean. jet black means you are rich. you may want to increase your main jet by 1 and keep increasing until you get a light brown.

[spliffy]

So That Brings Me Back To The Original Post.... What Do I Do? Smaller Jet For Leanness Cuz Of Bogginess On 3/4 - Full Throttle , Or Bigger Richer Jet Cuz Of Plug Color Already.... The Guy I Bought This From Put A New Air Filter In It , It Is Well Oiled.... Is It possible To Have To Much Oil Or The Wrong Oil On The Filter Therefor Blocking Air??:confused:

anything is possible bud. if i were you, go out and buy a new air filter. therefore, you know what it has. i doubt the existing filter is blocking the air. as you mentioned, the main controls 3/4 and has a huge impact on the performance. if you are running lean (whiter plug), you need more fuel....hence, a larger main. go up one at a time and see what happens. you would rather be rich than lean. being rich will only foul plugs.

[spliffy]

k , Thats Kinda What I Was Thinking.... Trial & Error Basically , Thanks For The Replies

[nakomis0]

Try going 1 smaller on your main jet.

You say your plug is boarderline white. But that could be from your needle being set to lean.

If you want to find out the color of your plug for your main jet, Run the bike at WOT for a minute, or so then shut it off immediately (don't slow down).

But like I was saying, run with no lid or try stepping down your main.