At full speed in 5th gear on my 1990 YZ 250 WR (wide ratio) the rear wheel locked up. I turned off the engine. I was able to start the engine again on the 1st kick. I was able to ride back to camp in 5th gear very slow over 2 miles away; very consistant throttle. There is a noise in the engine while in gear and you can hear it when the engine is running, but it does not take away from the engine performance. I started the bike 2 hours later after letting it sit and it started on the 1st kick again. I have heard that the WR is know for a transmission issue but I can not find any info.

SOURCE: Could you pls help me with a diagram of the cooling system

hpe these help

SOURCE: CONVERT A YZ 250 INTO A WR 250

The YZ is a dirt bike as is. The WR is a street bike and has more accessories on it.

• Remove the body parts you do not want to get broken. Turn signals, tail light, speedometer, tachometer and mirrors are the main things. Fenders and headlight are possibilities also but the fenders tend to keep mud off the the engine and your body while the headlight allows you to ride at night.
• Change to a larger rear sprocket. Two or three teeth will make a difference. This will make the bike to " quicker " off the line and out of turns and provide more torque than stock. Top end is a bit slower but with all the twists and turns you seldom get to top speed anyway.
• Get a heavier flywheel. Yamaha has one but the cost is about $105.00. An aftermarket flywheel may be an option that would cost less.

SOURCE: yz 250 2008 possible 5th gear stripped?

I doubt that any gears are stripped. Believe me you would have known it when it happened at 40mph which is where you would have to be in 5th gear. This is a bent shift fork. The actual gear is fine. The slider gear is not moving far enough to engage with 5th gear. The YZ does tend to have this problem in 5th and 1st. "Dirt rider Magazine " did a story on it. Best to let the shop do the repair as the entire motor gets torn down into about 100 parts.

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Murtaza Akberali Versi

• 767 Answers
• Posted on May 10, 2009

SOURCE: 1994 yz 250 bogs down

Have you cleaned the carburator ? It seems the main jet has some kind of obstruction.
Try cleaning the carburator and well a tune up would be fine too after the clean , check the plug/s & air filter too.

SOURCE: hi will a yz 250 1990 barrel fit on my 93????

It should if the diamiter is the same. Get some info from the person you are buying it from, then take some measurments on your 93 to see if it's a match