Need jetting recommendations

99 WR 400 FMF powercore iv stock header airbox cover removed, WR timing. Stock needle stock clip position

Just changed the stock 168 to a 170, and cleaned out the pumper circuit.

It feels flat off the bottom until onto the main. fuel screw is 2 3/4 turns out with the stock PJ Not sure what it is on a Canadian spec? 48?

Altitude is 2800 ft up to 5500 normally. Any baselines recommendations from others running simalar setup would be greatly appreciated.



[This message has been edited by fershy (edited 07-09-2000).]

No responses? C'mon guys, tis not an ol boys club is it?

Help! Please?


You will need to pull the pilot jet out and see what size it is, and then go from there. I would say try a 48.

As the Canadian model is the same as the Aus. model, and they come standard with a 45 and I think you should start at 1-1/2 turns and work your way out.

Mine had that problem, and the next pilot jet up fixed it.


RodH Canberra, Australia<A HREF="" TARGET=_blank>

400 Thumpers Australia</A>

2000 WR400F See Photo's and Modifications

Try to go up one on the pilot and if that doesn't work, move the clip down one position to raise the needle. I have a US 99 WR with a similar set-up.

Remember one change at a time (baby steps) and keep notes}:-)

Good luck



86TT225, 98CR80, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA.


The settings you described are usually good ones for most '99WR's. Let us know if the increased pilot or richer clip solve your problem.


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