950 miles on my WR, engine siezed today!!

Was able to get away to ride this weekend, first ride of the year. Bike was running like a champ, then we stopped for lunch. After lunch I start her up and it is making a really irregular clatter noise from the top end that jars the bike whenever it makes the noise. After warming up the noise stopped and we took off toward home. About 1.5 miles in the engine just siezed up and we skidded to a halt. Now I can't even kick it over. I'm thinking I dropped a valve or something. I can't believe how bad this blows. I maintain the bike very well as far as oil changes and air filters go, but I had yet to check the valves. Do you guys think it is a valve issue? Guesstimate how much do you think this will set me back?


I have no idea, but please post what you find out--mine is an '04 also, and I have around 750 miles on mine. I have checked and adjusted my valves once, after break-in.

Well, I have an 04 and about 550 miles. I'd also like to hear what it ends up being. I would check to see if the engine will roll a little bit backwards. I know it wont kick, but if a bearing/piston had seized, it would be solid. I would either roll it backwards in low gear or remove the stator cover and roll the engine over backwards. See if it will move a little, this could indicate a dropped valve. If it doesnt roll either way, then its more likely a bearing/piston issue. Of ocurse, trouble could still be just in the gearbox itself too, includes the clutch. Either way, I bet it will be a bit spendy.

My gramps suggested I do the roll backward in low gear trick, it wouldn't budge. I'll keep you guys informed.

did you winterize it? before putting it away for the winter.

I changed the oil the day it entered storage, probably back in November.

How much did the bike run before lunch stop?

About 30 miles, and it ran just fine with no unusual noises.

Are you sure it's not the transmission? Top end failures are pretty rare on these bikes. If you pull the clutch in will it kick through? Can you roll the bike with the clutch pulled in? When I got my '03 the previous owner had broken a gear in the tranny which in turn bent the rod when it locked up at high speed.

Kickstarter won't budge no matter what. With the clutch pulled in it will roll but there is quite a bit of resistance.

It's pretty normal for there to be drag when rolling the bike cold so it sounds like it is on the engine side. First off I would pull the valve cover and make sure everything looks ok there. Also pop off the center plug on the magneto cover and see if you can rock the crank either direction with a socket on the flywheel nut. When turning the flywheel backwards you will be engaging the starter clutch so some noise/drag from the starter is normal. You may want to pull the right side cover as well and make sure everything is ok on that side. In either case it sounds most likely to be a valve or rod problem. My guess would be the rod though most times that leaves a hole in the cases if it actually breaks. Hard to say what the cost will be. Depends on the damage and if you can do the work yourself or have a shop do it.

only 750 miles :banana:

well theres really no good news that I can think of to tell you. Its gonna be expensive. If you do it yourself you will save a ton of $$, and if you cant get it back together you can always hand the mechanic your bucket of bolts :ride:

tear it apart and see what happened, then you will no what its gonna cost.

I would be very surprised if it is a valve issue, maybe if we were talking about a Honda but not a Yamaha. I have an 03 with close to 8000 miles on and the valves are still in spec. sounds more like a bottom end problem. did you check the oil level before riding?

Yeah I checked the oil level a couple times throughout the weekend, it was fine.

Well I just got back from the mechanic. I was able to watch him work and tear into it. Just as suspected it was a valve issue. It broke one of the intake valves. To be more accurate it shattered it into a million little shards. The head and piston are toast. There are some really deep gouges in the head near the spark plug and the piston was punctured, and also very gouged up. I'll also need a timing chain, the one that was in there was stretched and kinked. Luckily it looks like the cylinder and crank are OK. It doesn't appear that any pieces of the valve made it past the piston into the bottom of the engine. I forgot my camera to take pics but I'll take some when I get the parts back and show you guys. Total damage is approximated at being $700 for parts and $300 for labor. Nothing like spending $1k on not even a 2 year old bike. :ride::busted::banana:

Wow kinda amazing what a valve will do when it smashes into the piston. Really stinks that it happened to such a new motor :banana:

Wonder why it happened, you say the chain was stretched and kinked, which could of happened from the lock up. Was it a valve retainer? Chain tensioner? chain guides? It would be nice if you were able to ascertain what caused it so it dont happen again.

well your getting a bran new motor now :ride: Good luck, could have been worse

I'm shocked to see an intake valve go at 950 miles. Exhaust maybe (due to closing up of the clearences or huge over rev) but an intake? Had you changed the cam or cam settings ever? The cam would need to be really advanced for the piston to hit the intake. Only other explaination would be bad valve seat comming loose, faulty valve or tight guide from the factory, crap getting into the motor and jamming in between the seat and valve, loose cam chain (but if it slipped it would retard the cam and hit the exhaust valve). Did you ever roll backwards down a hill and have the motor turn backwards? Did the motor rev OK before it happened? It would be great to get to the bottom of this.

Just another thought, sounds like you had the bike siting for a while, did you run the bike after cleaning it before you put it away, and did you store it with the valves closed (TDC on the compression stroke)? Maybe the guide, seat or valve got rusty while it was sitting.

I did do the grey wire mod. Never remember the bike rolling downhill backwards or anything of the sorts. Before storing for the 2 winters that I had the bike I would just change the oil, start the bike to get it circulated and shut her down. I never bothered to find TDC. Maybe I should have :ride: . I'd love to find out the cause of it, too. Maybe just a poor quality valve? What really boggles my mind is that it was running like a top for the first half of the day until lunch, then it just snapped.

They stop at TDC automatically.

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