Do you guys rejet like the WR side?

8 replies to this topic
  • chabon99

Posted July 14, 2002 - 12:36 PM


I've had my carb out a half dozen times with as many jetting and needle combinations and it still doesn't run as strong as a YZ. Do you guys do anything at all or just run stock jetting and enjoy your ride? Am considering sacrificing the WR lighting (and extra weight) and buying a YZ.

  • yznvegas

Posted July 14, 2002 - 04:09 PM


You can re-jet all you wan't but your wr will never be a yz. They are different in almost every way, gearing, timing, weight, and handling.

If you want a little more crack I think you can actually do yz timing on your bike (I know you can on the 426). Do a search and there is a ton of info on that.

  • MN_Kevin

Posted July 14, 2002 - 04:35 PM


Unless you exclusively want to race MX, the WR is a better platform w/ which to work. This IS NOT a "pride in my bike" thing. I got over that stuff about 20 years ago. :)

Changing the MX gearing on a YZF to a WRF is almost cost prohibitive.

There ARE gains to jetting the YZF carb. The WR guys have been FORCED to look for gains, therefore have more experience w/ it.

  • skthom2320

Posted July 16, 2002 - 03:41 AM


Unless you exclusively want to race MX, the WR is a better platform w/ which to work. This IS NOT a "pride in my bike" thing.

I don't think so. I don't race MX at all but I have a heck of a lot of fun anyway on my YZ. I'd be irritated if I had to remove 14,000 things just to have as much fun.

The only thing I don't ride is single track in the forest. I apologize to those who like it but it's a yawner for me.

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  • Shawn_Mc

Posted July 16, 2002 - 11:01 AM


Chabon to answer your question, jetting on the WR and the YZ are different because the cam timing is different. The cam timing changes the pulse the engine generates on the carb. If you YZ timed your WR the YZ jet specs will work for ya and you'll get the punch from the motor your looking for. If you dont want to did into the cam timing, getting your jetting right is very close to what is stock I believe.

  • Hick

Posted July 16, 2002 - 11:41 AM


W/ regards to jetting I haven't noticed any change when changing timing on a WR. To me the obvious difference is that ridiculous exhaust and airbox lid. Thing is strangled as delivered, that is why jetting is more of an issue for WR owners, because I've yet to see or hear of one who didn't "unstrangle" or "YZ" their motor to at least some extent.

  • PumpkinHumper

Posted July 16, 2002 - 02:39 PM


Ive never changed the jetting on my 99 yz400. The only time I mess with it is when the temp hits like 2 deg. and even then its just a main jet change.

  • chabon99

Posted July 16, 2002 - 06:42 PM


The jetting changes I've made were after changing the timing and exhaust to YZ specs over a year ago. My question is why it still lacks the power snap (it's very close) of the YZ when it is now essentially the same machine(+15lbs)?

  • MN_Kevin

Posted July 16, 2002 - 08:15 PM


Have you checked into the BK mod w/ regards to the accelerator pump? Bottom end response can be considerably improved with this mod. If is good enough for Team Yamaha, it's good enough for me!

As for the WR being a better platform, it is MUCH more versatile out of the crate. For $100.00, I received my WR from the dealer w/ a legal title and a license plate. I can dual sport, ride Turkey Runs where legal registration is required, ride my street legal race bike to the single track areas down the road, etc.

4 weeks ago I stripped off my headlight and tail light, stuck on my front # plate (I use a YZ rear fender and mounted an ACERBIS tail light) and hit the motocross track.

Granted the f-ing carb sucked to work with INITIALLY, but after the YZ timing and correct jetting, I couldn't be happier. :)

[ July 16, 2002: Message edited by: NH Kevin ]

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