250-500cc WR 300 gearing? Stock or...?

I am in need of new sprockets and a chain for my WR 300. What is the best combo you guys have come up with? Bike has a Keihin and a full FMF exhaust system. Bike will be used primarily for enduros.

funny you are asking i was just doing testing on mine. i ride tight single track and 4th gear and up is only used on the jeep road. i kept the stock front sprocket. the bike came with a 49 rear and it was way too fast for my riding in 1st gear. i was constantly slipping the clutch. i bought a 50 and tried it. much better for me. but im at a 52 now and im on the fence about it. it tractors up anything but if i need to clutch it up to get the front end up i must be very careful. and the top end is rather low, but like i said where we ride you never see 4th unless on the jeep road headed home. i have a race coming up on the big island of hawaii. called the mauna kea 200. 180 miles in 2 days. this tells me right away im gonna need to drop my rear sprocket to keep those kinda speeds. i think the 14/49 or 50 will be good. depending on the pace of your races anywhere from a 49-52. i usually dont change the front ratio becasue going down changes the angle of the chain and eats you slider. so to answer your questions try 14/49 and adjust if needed. that ratio has good top speed but also plenty of low end grunt as well, however you might need to slip the clutch to get the front wheel up from super low speeds (1-4 mph)

I'm running 13/48 now, which is stock. Will I need a longer chain with 14/49? Stock is 114 links.

nah you shouldnt unless your rear axle is all the way forward. its always nice to have several sprockets around and a longer chain if you go real big on the rear. that way you can try different gearing and find the gearing you like for each type of race. now this is a big debate but i do it and flat track guys do it. instead of having 2 chains i have 2 masterlinks. i have two on there now because i have a 52 rear, but when i put the 50 on the chain will be too long. then i remove the extra master and im back to normal. like i said some people are going to disagree with this saying the master is the weakest link blah blah blah. its not and a chains tensile strength is tested with the master link installed.i have never lost a chain or master link or clip for that matter. but that is a whole other disscusion. lol

14/50 trails
15/50 dez

I hate changing rear sprockets and this bike has more than enough power to pull the 15.

pc with that 15/50 what is the cruising speed in 5th gear do you get?

It did 70 with stock gearing down at China Hat and I'm guessing 15/50 isn't too far off from 13/48.
70mph wasn't cruising speed though... it was about to send the piston through the head! It would cruise semi-comfortably around 50-55mph I'd guess.

This bike NEEDS the 6 speed!

Those ratios are pretty close actually..
14/50 = 3.57
13/48 = 3.69
These two are very close and I cant really feel a difference between the two.

15/50 = 3.33
This ratio can be felt and certainly adds a few MPH to the top.

Fire - Off topoic, if you still have the expansion chamber off the '08 wr250, drop me a note.
John_Hunter@genpt.com