9200 miles on my WR

[Cooksend]

Ok WR guru's. I have 9200 miles on my WR450. It has dual sport, singletrack and harescramble type riding. At about 8,000 miles my valves came out of spec for the first time! I know amazing ey! It has finally started to puff a bit of smoke and I am thinking it is time to do some motor maintenance. Of course money is always part of the equation but so is doing it right. I have not checked valve clearance and couldn't tell you it they are within spec at this time or not. That will be done very soon. I was thinking about just slapping a ProX piston kit in it and running it for another couple grand but really want some input.

If this was yours what would you do and why?

[FORMA MOTO]

If you haven't damaged the cylinder by going such a long time on the original piston and wrist pin, then great.

I wouldn't bother opening it up without changing everything above the rod, sans the exhaust valves, and head.

[Cooksend]

If you haven't damaged the cylinder by going such a long time on the original piston and wrist pin, then great.

I wouldn't bother opening it up without changing everything above the rod, sans the exhaust valves, and head.

I hear ya! I know that is the correct thing to do and my wallet says to check valve clearance to see if it's in spec. If in spec throw a top end in it and go. Guess I had better take a look at it.

Anyone do a head exchange on Yamaha's? Wiseco or ProX Piston kit?

[FORMA MOTO]

I hear ya! I know that is the correct thing to do and my wallet says to check valve clearance to see if it's in spec. If in spec throw a top end in it and go. Guess I had better take a look at it.

Anyone do a head exchange on Yamaha's? Wiseco or ProX Piston kit?

oem oem oem

[n16ht5]

You need to pull it all apart before you can start expecting anything. Your head could be OK, you don't know until you get it apart. Have you ever inspected the valves?

[Cooksend]

I have been checking the valves every 1,000 miles or so and had to do the first shim at about 8,000 miles. It was amazing and only one needed to be shimmed! The bike still pulls like a freight train but is starting to smell like a smoker when you get behind it!

[n16ht5]

Well that's a good sign. Bare minimum you will want wrist pin, piston, rings, cam chain

[Strattos]

What about cam chain and tensioner?

Ive heard some guys swear by changing these as well for peace of mind if you're pulling the motor down anyway.

EDIT: just noticed post above mine already mentioned can chain.

Edited May 17, 2013 by Strattos

[SteveThe Snakes]

Not so sure how many miles are too many miles on a wr450. Seems as a saw cut quarter of an R1 street bike. They go many many miles. Think I have over 10,000 on my supermoto wr450 stock piston doesn't loose a drop of oil.

In other Countries they are sold as street bikes.

[Strattos]

Seems I've got plenty left on mine then. Just ticked over 9000ks on my 08 model. Only problems I've had are water pump seal and countershaft seal. Valves still in spec and doesn't use a drop of oil.

[MaxPower]

Not so sure how many miles are too many miles on a wr450. Seems as a saw cut quarter of an R1 street bike. They go many many miles. Think I have over 10,000 on my supermoto wr450 stock piston doesn't loose a drop of oil.

In other Countries they are sold as street bikes.

R1s aren't ridden in an environment where they can potentially get some kind of dirt through the engine.

[Cooksend]

So the motor is torn down and it is looking like the rings started to fail and caused lots of carbon on top of the piston. Carbon deposits are hard and did some damage to the valves! In turn I will put a pair of exhaust side valves in and have the seats cut. Add new springs to these and throw a top end at it! Not bad for the miles on the bike!

[FORMA MOTO]

So the motor is torn down and it is looking like the rings started to fail and caused lots of carbon on top of the piston. Carbon deposits are hard and did some damage to the valves! In turn I will put a pair of exhaust side valves in and have the seats cut. Add new springs to these and throw a top end at it! Not bad for the miles on the bike!

Have you mic'd the cylinder to check it's service limit?

[Cooksend]

The cylinder is A'ok! Yes is was mic'd.

[NitrousR1]

I'd replace the piston rings wrist pin cam chain- tensioner should be fine. Also pick up all 5 valve seals, easy to replace and could be contributing to your smoking. Also time to think of stock or high compression piston

[Cooksend]

Done and ready for a test ride! New top end and the head is redone with valves and springs! Should be good to go for another 10,000!

[Cooksend]

Well I have about 200 miles on the bike since the rebuild. It started first kick and ran great. Now after about 200 miles the bike does not want to start! I have to struggle with it to get it running. Back to the garage to work on this. &%$#@!

[o313]

Any more news on what it was?

What brand of parts did you use?

[Cooksend]

Any more news on what it was?

What brand of parts did you use?

 

Well last year I did not get a chance to ride.  This year I am hoping that will change!  

 

The OEM parts were replaced with Pro X pistons and valves.  I am wondering if maybe jetting would need to be changed because of this?  Maybe a different dome on the piston or some change in the valves?    

My thoughts, when cold the bike starts easily with just choke.  It still becomes difficult to start at times (not all the time).  I have typically run with a silent insert in the stock exhaust to make it friendly around town.  When I put this in the bike runs like crap, remove it and it pulls hard (not as good as it did before the rebuild).  My thought is that with changes from OEM to the Pro X I may need to lean it back out a bit.  Anyone have a Pro X set up running at 1500'?  Jetting?

[bikedude987]

probably just the valves seating.  Unlike the stock Ti valves, you'll have to shim these often, probably.