I checked the T P S on my 99 WR4.

Black to Blue = 4.9 k ohms throttle closed

Black to Yellow = 800 ohms throttle closed

When I calculated this as per the manual it looks to me that the TPS may need adjusting.

The bike runs fine but it just dosn't have that snappy throttle response.I have gone right through the jetting and it looks to be o.k.

Do my TPS reading look o.k and is there any benifits in adjusting it. If so what should lt be adjusted to and how do you adjust it or is it advisable to just leave it alone. The manual dosn't describe this very well. I have WR timing , Yz timing didn't work for me.

Any help would be greatly appreciated.


There is a allen head screw w/ some loctite on it on your TPS. You must loosen this and you will have a smidgen of movement. As to whether or not it will do anything...well hopefully Clark or James can clue us in. I too need to adjust mine. Per Larry Roessler, I went full clockwise to richen the bottom up. After my jetting changes and YZ timing, Clark recommends I go back to stock position. Unlike Crazy Mike68, I am not riding my bike in the dark up here in New Hampshire :). It doesn't help that I am in the middle of finishing (starting?) off my basement and my bike is inaccessible and cannot be moved [drywall and studs (no, not me :D) in the way}.


'99 WZ with all YZ mods, FMF PowerBomb header, Stroker SX-1 silencer, SS front brake line, forked over by Pro-Action, OEM YZ tank and IMS seat.

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