Accelerator Pump and TPS


Can you give me some information on checking the settings of both the accelerator pump and the TPS.Information of what they should be would help. I am pretty sure the ignition timing seems a little retarded on tick-over, could the TPS setting cause this. I am running a 180 mj, 48 pj and dtm needle on 4 clip with pilot srew at 2 turns. WR with YZ timing, FMF PC IV, FMF header, air box top removed. Altitude 100-1000 feet.Your help would be much appreciated.

I am from the UK will visit the USA next year to try some hare and hound events or even good rideouts. What would you recommend not to miss ? whats this Moab thing ? Look forward to replies. :)


IMO James Dean and Clark Mason are the resident FCR experts. If you read the topic titled “James Dean – Accelerator Pump” started by me 10/8 (it should be way down on the bottom) James gives a good description of the stock pump setting as he found it.

I believe you need an Ohm meter to check the TPS. One thing I would like to know is what kind of bit or driver is needed to get the TPS off (it looks like a torx with a dimple in the middle on my 426). I’ve never checked mine. Why bother if you can’t move it?

I for one am tired of hearing about Moab :) (jealousy is powerful emotion)

Hope this helps!


What is described in that post (1 turn on the screw) was for a 2000WR. If yours is a '99, there is a accel pump arm gap of .6mm at the "forked" arm under the black carb cover.

The TPS resistance is described in detail in the manual.

Your jetting sounds rich from idle to 1/4 throttle, DTM#4/48/2 turns, how does it run? would 1 turn run any better? Just curious.


The pump should squirt nice and evenly--

That is all I know about those--

The TPS on the other hand----

Take a DVM and put on ohms-

if ya got gattor clips to hook to it thats even better---

Put the throttle thru the motion from closed to full open!!!!!!

Nice and evenly~

If the ohm rating does not go up smoth and evenly "If it blip's , jumps whatever"

It is no good!!!!!!!!!!!!!!!

Hope this helps!!!

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