WR 400 question

My 98 WR willmiss as if it is hitting a rev limiter when I am on the starting line trying to clean the engine out(like I used to do on my 2 strokes).It doesn't seem to rev very far when this happens.I swapped CDI's w/ my friends WR and it did the same thing.My question is-does everyone elses WR do this?If so, does anyone know if a YZ CDI will directly swap w/ my WR's box?I have never noticed this before and I have owned/raced the bike for over 2 years in the A class.


your probably running very rich indeed.

wash & renew the air filter.

clean out the carb. reduce the pilot screw until it starts to gently back pop on a closed throttle slow down.

that will do it.


This could be wrong, but I thought there was a special ignition map when in neutral. A lower rev limit was designed to avoid overrevving when missed shifts occur.

The jetting is probably OK, unless you feel there are signs of it running badly. Cleaning the carb never hurts!

Mine does the same, so do YZ426's.

Not quite sure what you feel the need to "clean the engine out". Clean it out of what?



Not to offend, but it's not a two stroke and does not need to be "cleaned out".

I let my bike idle for 10 minutes when I get to the track and put on my gear. If I trail ride with my son and he falls. I let the bike idle while I help him. Then jump back on and "pin it", It's never "loaded up"..... it's not a two stroke :)



97 KDX220, 86 TTR225, 99 WR400f, WR timing, 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.

I guess I just rev it on the line out of habit(from the 2-stroke days).Anyways, the carb has been cleaned as well as the filter-w/o too much oil.Plug is slightly tan color.I have not changed jetting recently,but after the problem occured,I removed the octopus to see if it made a difference but it did not.I am going to change needle,ect. as per the recent posts on the subject.


Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now