03 WR450 will not start - any advise

Wr450 started to blow smoke under high revs but started ok and had stacks of power. I decided to get it checked out as I did not want to cause any further problems. Well it ended up the cylinder was scored. Cylinder,piston, rings, and valves were replaced by a motorbike engineering place.

First ride was a four day ride in the desert.I lasted 65klms and then the bike would not start. I took it back and was advised the timing chain skipped a sprocket and timing chain and tensioner needed to be replaced. I said ok.

Next ride out the bike lasted 28klms and then would not start.It took 4 hours to get the bike out.

Fuel is ok, Has spark. Bike will back fire when you kick it but will not start. I have so far spent A$2500 having the bike repaired. Feeling pissed at this point.

Any Ideas?

Sorry for your troubles! You need to find a better shop to fix your bike. The 03 had flywheel problems check for the problems here on TT. It does sound like the flywheel has spun on the crank and you are off on ignition timing. If you do the search on TT you can find the problem and the fix. Good luck!

Thanks for the advise. I will have a look.

Took the bike back to the shop and they opened the inspection cover. The fly wheel nut was loose. Not sure if there is any damage yet The mechanic has said it is not his fault but forgot he replaced the the starter clutch. I will need to remind him.

Time to work on the bike myself.

Can anyone tell me if the flywheel needs to be removed to replace the timing chain?


Hey I have a 03 wr450 and no problems . BUT I have heard that the key in the fly wheel will break or come out and it will throw off your timing and will not start. That would be my first thing to check ,pull it of and really pay attention to the key way.. good luck

Flywheel nut was loose? and not his fault? whose fault would it be if not his? He did not have the flywheel seated properly to the crankshaft. So the nut became loose when the flywheel moved, his fault. Both the starter clutch and timing chain need to have the flywheel removed to work on. You need to inspect the flywheel key cut in the crankshaft and need a new flywheel key. The new key needs to fit tight in the crankshaft. The flywheel can be mated to the crank by using fine valve grinding compound to remove high spots so it can seat properly. Also the factory recomends using loctite, be careful so it does not get in the starter clutch. There is lots of information on this subject on TT. Try flywheel problems and see what you get. Good luck!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now