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transmission problem

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I have an 03 YZ250F with a 5th gear problem. When I get into 5th and when I'm on the throttle more than about 1/4 open the bike jerks as if I was pulling in the clutch and letting it out extremely quickly while accelerating. Does anyone know what is going on? It has been getting progressively worse and it is really annoying especially when I'm ice racing.

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The locking dogs (lugs on the sides of the gears) on 5th gear and the gear that locks it to its shaft are worn so that they force each other apart under a load, instead of holding together as they should. The shift fork will also be damaged as a result.

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Now that I think about it I took off my flywheel to replace the stator last year and I remember finding 3 small pieces of steel stuck to the magnet on the inside of the flywheel they must have been pieces of the lugs that got broken and found their way to the flywheel magnets. As far as I can remember that was when the problem started.

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did you fix it? and if so how difficult was it?

you will need to split the cases to do it, but if your familar with doing that, it shouldnt be hard at all

if you never split a case, take it to a shop or have someone that knows the proper way, show you how

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I have an 03 YZ250F with a 5th gear problem. When I get into 5th and when I'm on the throttle more than about 1/4 open the bike jerks as if I was pulling in the clutch and letting it out extremely quickly while accelerating. Does anyone know what is going on? It has been getting progressively worse and it is really annoying especially when I'm ice racing.

I'm sorry to announce another member of the '03 broken tranny club.

I'm a two time member myself.

You're fortunate that the teeth got hung up in the magnet. There will be metal that has gone thru your oil pump so inspect it thoroughly and put a new pump gear in ( it's a cheap part) and a new timing chain.

Good luck.

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