250-500cc wr300 gearing

Hi guys,

Pretty close (hours) to buying an 09 wr300. This is going to be my trail bike and I am VERY excited.

I was just wondering what advice you would give me for gearing this down? What's the biggest rear sprocket I can run with the stock chain?I am looking for gearing that will let me crawl up the technical stuff. I am getting a plate for this so while I will be riding the occasional road top/high speed is not really a concern.


I am essentially a lurker on this site and others as I rarely have anything of value to say but I will soak up any information you have for me.
thanks.

I bumped up 2 teeth on the rear. No fitment issues. And it is fast.

I'll run the stock rear sprocket in the desert and gear up 2 for the woods.

Is your countershaft sprocket a 13T or a 14T PC?

I believe its a 13 as I think that is what comes stock with these bikes.

Maybe I'm wrong. Thats certainly happened before.

I'm running 13/50 and really like it for the woods.

The spec sheet says the bike is supposed to come with a 14T front, but most have a 13T.

Yeah, that's what I've got...13/48, and I just can't imagine wanting it geared any lower. I've read where people said their WR300s would hit 70 mph with the stock gearing,...didn't you say that once PC?
Point is I'm wondering if there's two different trannys because I'm telling you mine wouldn't hit 70 if you dropped it out of an airplane.
It's wound up as tight as I can bring myself to push it and screaming at 50 mph! Wonder what the deal is with that? I've got this thing dual sported now and was going to hit a few AMA D/S rides this fall,...but if I don't go to a 14T on the countershaft I'm gonna get run over on anything more than a secondary county/township backroad!

Have you tried a bigger main jet?

No, it's got that 460 in it stock,...I've not yet heard of anyone running anything bigger than that.

It's not a fuel delivery problem,...it's extreme RPM. At around 50 mph the thing is screaming at 1/8 - 1/4 throttle down on the pilot and needle.
It's never even been on the main jet in 5th gear except for just short bursts. The thing is just geared too low.

That's weird.
I took the bike out to the desert right after I got it (bone stock) and my gps recorded a top speed of 68 or 69mph. I had it completely wound out in 5th to get that speed.
It will comfortably ride at 55-60 and still have power on tap.

The 68mph ride was at 4000-4300ft, jetted fat (stock jetting) and the motor was still a little tight.

I now run 35pj (needs 32.5), stock needle #2 clip, 450 main. Float height was at 6mm, but recently adjusted to 9mm. It's perfect up top.

Have you removed the chain and did a hand count of the sprocket teeth? Maybe they stamped the wrong numbers on it
Good luck tracking down the issue.

I picked up my WR a couple of weeks ago. I rode it once with the stock 13-48 gearing and then changed to 14-45. I've ridden it once with this gearing and I'm pretty happy with it so far. I haven't tried anything really gnarly yet so I may end up going to 13-45 if it's too high.

I dunno,..........
I'm only going by the stock speedo,...but the odo is pretty spot on when I ride a measured mile, so you'd think the speedo would have to be fairly accurate then as well.
Another thing that I'm wondering is, could "completely wound out" mean something different to me than it does to you PC?
I'm admittedly a little squeamish about wringing a motor out. I can't hardly bring myself to hold a bike pinned 'til it sounds like a chainsaw.
Call it 'mechanical sympathy' or whatever, but that just makes me grit my teeth. My style is more to short shift it and lug it a bit and feel that torque. Maybe they'll make a diesel WR300 for me one day.
Sounds like nqjim & I might think alike though.

I'll count my C/S teeth tomorrow just to be sure. I'm not taking my chain off to do it though,...I'll put it up on a stand and make a white spot on one of the teeth with a paint marker and roll the wheel.

As for tracking down the issue,...the issue as far as I'm concerned is that this thing shoulda had a 6th gear.

the countershaft sprocket is a 13 on this bike. I am leaning towards the 50 on the rear as this will be primarily a single track bike for me. So, top speed is not a huge deal for me.

I took mine for a good ride on the weekend and I'm very happy with the 14:45 gearing. We hit a couple of long, steep, dusty, rocky hills and the bike just kept pulling until rider error kicked in. The higher gearing spreads the gearbox out quite nicely. Still needs a sixth gear though...

The easy answer guys is to put a 6 speed in it. All you need is to find an older 250/360 like Kelly did and switch the trannies. Of course if it is as clean as Kelly's you may have trouble parting it out.

Walt