Change jetting when removing air box cover?

I have removed the air box cover, and am using a Baja Design baffle. The bike runs real strong, but I am wondering if this will be running too lean? I am using the stock jetting and don't have any flat spots. No complaints. Other than checking the plug, what other signs of too lean are there? I have the Dual Sport ride in New hampshire this weekend, and hope I can get some info before tomorrow noon. Thanks

If the bike backfires when you let off on the throttle. It's an indication that the fuel screw or pilot jet needs to be richen'd. If you ride at wide open throttle in 4th or 5th, then hit the kill switch (don't forget to pull in the clutch:eek :) now check your plug again, you'll know if the main jet is to lean.



97 KDX220, 86 TTR225, 99 WR400f, WR timing, MX-Tech suspension, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. De-octopussed. Works frame guards and Thumper Rad Guards, Scotts steering damper. Odometer and headlight removed. Cycra Pro-Bend hand and mud guards. YZ stock tank, IMS seat and number plate. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA, Happy Ramblers MXC, Rausch Creek MXC, Tower City Trail Riders.

In the old days for 2-strokes, it was wide open, 4th or 5th gear, for one mile to check the main jet.


'99 WZ/YR (you choose!) with ALL YZ mods, de-octopused, DSP Doug Henry airbox w/ velocity stack, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, forked over by Pro-Action (and then fixed by me), OEM YZ tank, IMS YZ seat, carb mods by Jim Dean, Andy in OZ, & Sir "Taffy" from Jolly Old England, AMA, NESC, and I use MOBIL 1 Oil, with ZERO problems.

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