Technical help required PLEASE

Hey guys i am having drama after drama after drama with my WR450f 2003 model.

I brought it with a broken kick starter shaft that had broken the case.

Now i fixed all that and got the bike running.

It had no battery so i broght a battery and fitted that to find it still wouldnt start. Found out it was the solenoid relay faulty.

So got a new one of them and fitted it..... YES the starter then wound over BUT to find that the starter was no good as the teeth on the starter shaft had worn down and it was just slipping inside the gear :cry:

SO i finally got the new starter motor and just fitted it and guess what it still dont start. it is spinning the starter gear that joins to the starter motor but it wont start i dont think the lower gear is turning?

Is there anything that would stop this from turning as i havent pulled the motor apart. or how can i check to see what is going on as if i pull the little 2 bolt case off the starter gear it would fly off so i do it would fly off as there would be nothing holding it closed???

CAN SOMEONE PLEASE HELP ME this bike has costed me a fortune to try fix and i have ran out of ideas.

I know it hasnt had the update conversion done on the starter gear dampner it still has the solid gear fitted.


Thanks guys

from the FAQ page

Q: Are there any known problems in the various generations of WRs that I should be aware of?

A: The biggest one is with the 2003 WR450. There was a problem with the e-start, primarily with the woodruff key wherein it could shear off and cause internal damage. Here is a pictorial write-up detailing the fix, complete with part numbers. The problem was fixed for '04 and the affected '03s could be fixed with upgraded parts. There is a tutorial for the upgrade available in the Performance Index. Other more minor issues include cracks in the throttle slide that could eventually cause direct metal injection into the valvetrain. This was remedied with regular inspection and replacement. There have also been a few reports of premature transmission wear that caused various gears to pop out of engagement. This was seen in several bikes that were dual-sported and then saw street use with prolonged high speed cruising in the higher gears. As these bikes were not really designed to run at constant speeds of that nature, it was not considered a surprising result.

have a look at this as well


Failing all else, you'll need to pull the stator cover off and see if the big toothed ring on the back of the rotor is ok, and 'bites' onto the crankshaft when turned anticlockwise

This toothed ring is what the starter motor turns via the solid gear, to turn the engine over

if its not biting when turning forwards then you need to pull the rotor off to get to it to see why

maybe the bolts that hold the starter clutch to the rotor have sheared and so there's no drive to the crank, or the starter clutch is just knackered

Edited by GuyGraham

OK guys got a update.

I removed the 2 bolt cover and wound it over by the starter motor and it spun the gears off the starter and also the one that goes into motor.

So i removed the stator case cover and i can move the toothed gear behind the rotor/flywheel.

It spins both ways freely so what does that mean?

I tried to remove the flywheel/rotor, I removed the 17mm headed bolt but couldnt remove the next bolt the 24mm headed one???

I also dont have the correct flywheel puller i just have a 3 claw puller could i use that?

Is the 24mm headed bolt the same thread direction as the 17mm headed bolt?

If it spins both ways there's something wrong with it

Looking at it face on, it should spin freely clockwise, but not spin at all anticlockwise, as this is the direction the starter motor turns it to turn the crank to fire the engine.

When turning anti-clockwise, it should bite onto the crank (well its not actually the crank, but its the best way to explain it) so the crank is then turned by the starter motor

You will need a puller to get the flywheel off - they are on very tight

Fit the puller to the rotor, then tighten the centre bolt onto the end of the cranksshaft, and then hit the end of that bolt in the puller, retighten the bolt and hit it again. The rotor should pop off. Don't use brute force to just pull if off by ever tightening the bolt in the puller.

Do not use a 3 legged puller or you will damage the rotor

The 24mm 'nut' is part of the rotor and is what you use to hold the rotor when doing up the primary drive nut on the other end of the crank, or tightening the 17mm rotor nut

There are usually rotor pullers available on ebay

here's one for a WR450 2003 model, thats located in Aus

If you can't source one, perhaps a local dealer can lend you one

Edited by GuyGraham

ok i still havent got the flywheel off yet as waiting to take it to delaer to remove it but i was having a play with it and found that if i push the gear behind the flywheel towards the engine while i spin it counterclockwise it will spin a bit then grip. Then if i try spin it it wont. if i spin in clockwise it will spin the try spin it again counterclock wise it will spin freely again untill i push it onwards towards the engine.

What could that mean ???

The starter clutch is almost certainly knackered, or where the starter clutch rollers bite onto the gear is worn

Until you can get the rotor off to have a look its just guess work, but my money's on the starter clutch

Hey guys just a quick question does the flywheel bolts go the same way?

the 17mm one and also the 21mm one i think it was or 22mm?

or is the bigger one closest to flywheel left hand thread?

i got the 17mm one off normal thread but i cant seem to get the next one off?????

all good guys its part of the stator/flywheel.

but got a video of whats going on now as i have stator off

can someone help me out with thats happening?

The starter clutch, which is bolted to the back of the rotor, is knackered

As soon as you turn the gear in a forwards direction (no matter what speed) it should be locked by the starter clutch

Unlikely its a worn starter gear, but it could be

Look at the area that fits into the starter clutch - is is worn / damaged?

If you take the large gear off, you should see a serious of rollers which should 'bite' onto the part of the gear that fits inside them

I've never had a starter clutch apart - don't even know if its servicable

I'd have thought you could pick up a second hand one for reasonable $

Edited by GuyGraham

Thanks heaps mate the gear looks to be ok no wear marks or anything like that at all.

Is this the mod where everyone removes the clutch and fits a solid gear like the 04 models or is this a total different thing?

I would like to upgrade to a better year model part if there is one while i am at it so does anyone know what other year model part i can fit?

Thanks heaps GuyGraham for your help i really appreciate it.

No worries (as you guys say!)

The 'mod' is totally different - its to do with the gears in between the starter motor and the gear on the back of the rotor

The mod is actually to add a torque limiter clutch, so if the bike kicks back when being turned over by the starter motor, it doesn't wreck everything

If you're bike hasn't had it, then it would be a good idea to do it

the starter clutch is essential - it allows the engine to be running, and not transmitting any rotational force to the starter motor - without it, once the engine started, the engine would continue to drive the starter motor as there would be no way of disengaging the starter motor from the engine

model year 2004 parts are a retro fit

check out the link in my first post (post no. 2 in this thread)

Maybe, but I'm just speculating here, your problem has been caused by a kick back and its damaged the starter clutch, rather than the more usual damage further up towards the starter motor.

Edited by GuyGraham

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