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Flywheel Failure ? - 2003 WR250

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HI Guys,


I have recently purchased a 2003 WR250 which was sold as spares or repair, according to the previous owner, the bike started to lose power, he stopped it, then it would not restart, he tried to kick start it, then bump start it but it would not go.


When you press the kick start, sometimes the motor turns over but feels rough, other times it jams solid.


I decided to take a risk and buy it with a view to getting it back up and running.


So cutting a long story short, I stripped the head & barrel and checked the piston and crank and it was all just fine, which was a surprise, when I took the flywheel cover off, it quickly became apparent what had gone wrong - see pictures attached.


it appears as though the allen bolts have worked their way out of the flywheel and destroyed the stator coil, now the question I have is do any other later year flywheels fit this motor as I know the motor is fundamentally the same? however the later flywheels 2006 / 2008 for example look to be different so before a go out and buy one can anyone advise??


Also if I get a later flywheel will the 2003 stator still work with it and also the electric start gear?


whilst I am buying part, I recall on my honda CRF 250 I was able to directly fit a CRF 450 flywheel which was quite a bit heavier and transformed the low down power, would this be an option on the WR??


if anyone can cast any light on this for me I would much appreciate it as I am keen to get the parts ordered to get it back up and running and enjoying the power of a Yamaha for a change !!


Thanks in advance.



Edited by Dave_Askham

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Fitting the starter one-way is not going to be your problem...


Your flywheel is unique to that year WR250.    For the 2004 model Yamaha changed it and it will not fit on

the crankshaft.


The flywheel for the 2003 WR450 is the same, so that give you at least one additional option for finding

a replacement.


For stator, you are probably stuck with 2003 or 04 WR250 stator unless you want to change the plugs 

on the ends of the wires.



Oh and when you put it back together make sure you put loctite on those six bolts!    The previous owner

must have had it apart at some point and neglected that step...   you see the result.

Edited by DeepPurplishBlue

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