Simple q's about the WR426

Ive spent the last week searching through the archives on the WR426 and may pick one up tomorrow(2002). I few questions are still unanswered:

1)Removing the stock exhaust 'cork' improves flow/performance but will this make the stock exhaust louder?

2) Living in CA Im wondering what the noise level is for the stock exhaust either mod'd or unmodified.

3)I read someone who used the "Vortip" baffle. What changes will occur when using this baffle (ie. noise, performance,etc.)

4)What gearing came stock on the WR426?

5) Was the 'BK mod' necessary on the 2002 model?


1) Yes, MUCH louder! 103db, uncorked.

2) Don't know what Cali's requirements are...

3) No experience with a Vortip...although I imagine noise/performance is similar to that of the GYT-R or PMB inserts.

4) 14/50

5) Yes

i ride a 02 426


2) 96DB supposedly

3) Never used it

4) 14/50 but run 13/50 you will be VERY HAPPY

5) never did it to mine and has ran great ever since i took it home off the showroom floor.

I have the Vortip. I use to run an YZ pipe, too loud and no spark arrestor. I put the stock pipe back on and ran it without the insert, still too loud. Bought the Vortip, good performance and a lot quieter.

I would only do the BK mod as possible solution to off idle bog from quick throttle twist. Chances are you will have it. :)

I've lived with a bog for the 2 years I've now had mine. I'm gonna try the mod to fix it.

I had a 2001 WR426F and it had the stock muffler with a Vortip. Corked with the vortip was measured at 91 db's. Without the cork, way beyond legal public land limits.

Rock n' Roll!! :) Thanks for the replies fellas!

Looks like the one Im pickin up has the gytr insert. I guess as long as I keep it plugged Ill stay below the 96db limit.

I havent ridden it yet but the gentleman who owns it said it pulls from the get go. He also said he out pulled a stock 05' WR450 on the trails. We'll see :)

Rock n' Roll!! :) Thanks for the replies fellas!

Looks like the one Im pickin up has the gytr insert. I guess as long as I keep it plugged Ill stay below the 96db limit.

Yes, you'll end up righ at about 92 with the GTYR. Well under the max. Now you can head out into public lands and tear it up! :)

I have also just purchased a 2002 wr 426. The Yamaha dealer in my town was owned by a real tool that wouldn't lower prices on anything. Due to this mentality, noone bought from him. Therefore; he had tons of non-current models(politically correct term for older models that have never been sold). A new owner bought the dealership out and is trying to blow out the old inventory. I grabbed one of the 02 wr 426f's two weeks ago. We have not had two days in row without rain since then here in H-Town. I have had the suspension dialed in by JM Racing here in Houston, and I installed the Boyesen Quickshot last night(still haven't tried to run it since my family was asleep when I finished). I uncorked the tail pipe and installed a GYTR insert, removed the air box cover, installed radiator guards, installed frame guards, (the dealership guys disconnected a wire under the seat, so I have a yellow wire connected to nothing), installed a pro-taper bar, and the bike has yet to touch dirt. It sounds good in the garage, and the weather should be sunny all week. I bought some engine ice for it, but ncmountainman and a few other said they had poor luck with it. So I left the stock stuff in it. I bought a case of my favorite high performance oil which is Motul 300V. It isn't cheap; however, it has the highest film strength of any oil that I know of. If the ground wasn't still wet, I'd play hookie today and go ride. Good Luck and if anyone has any ideas about improvements for the bike, I am interested as well.

Pretty cool that you found old/new WR's. If you dont mind me asking, what did they charge you OTD?

Congrats on your purchase. I purchased a left over 02 last summer here in Ohio. The yellow wire that you mentioned under the seat is for the rear brake light switch if you decide to install one. At least that is what I have been told. It does not come from the factory connected to anything.

Enjoy your ride and hopefully you will be able to get out and ride that WR before you wear out the seat from sitting on it all night.

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