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Ronnie Mac

valve ajust this week end

14 posts in this topic

Alot more head noise then I can stand. Have about 1000 miles on my wr450 and I know I need to check my clearance but this bike does intimidate me a little when it comes to some of its pre-maintance tear ins.Can any one give me any pointers on checking the valve clerance and replacing the shims. And what the hell is molybdenum disulfide oil, and whear do you get it. MY LIFE IS IN YOUR HANDS :)

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Moly disulfide is an assembly lube used to cushion metal to metal mating parts until proper oil flow takes over the job. Go to any hot rod store and ask for assembly lube and they'll hook you up. Use it liberally, as it will mix with the engine oil and disappear. As for the valve adjustment, a factory manual comes in very handy , which I assume you have. Just remember NOT to mix up any buckets if you have to change a puck. They are mated parts(from wear) with their matching bucket bore in the head and, if mixed, can cause serious damage to the bucket or head, so do each one one at a time before moving to the next. 1000 miles should not require a valve adjustment yet anyways, but who knows. Also be sure to have a thin blade feeler gauge as a standard width blade will not fit between the cam cap of #2 intake valve. Other than that, it's all gravy. Good luck. :)

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I checked valve clearance on mine last weekend. At 650 miles everything is fine , no adjustment needed yet.

These things do make a ot of valve train - piston noise. Especially if you have a skid plate on them. It seems to direct all the noise right up to the rider.

Lowedog

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Ronnie Mac,

These guys sure make it sound easy, don't they? Just the thought of having to do this frightens me. :)

Maybe this winter...

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As someone else mentioned, make SURE you chart where all the buckets/shims go as you take them out. They all need to go back exactly where they came from. (with the exception of new shims)

Watch out for the half moon retaining cam clip that will try to pop out and fall into your motor when you pull the cam caps off. Take extra caution here.

Ive seen several write ups on the subject. I even have one on my website (look in my sig) but not sure how it would apply to the 450. I cant imagine it would be too different (except for the removal of the compression release)

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THANKS :thumbsup:I really do appreciate all the good advice. I know I could just take it to the dealer for about $60 bucks(thats what dealer said whin I called about the availability of the shims) but I realy want to do this myself. So thanks again I will heed all your warnings. Thanks BlueThunder I well try my local auto-zone for the grease. :cheers:Its so nice to have a place to turn too for help. :):D

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I got all this done (and changed my cam timing) with all the help from these guys on here.

It wouldnt be possible without TT :)

Yamaha service dealers have to hate TT. Im sure its taken away a good chunk of business for them.

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One thing that screwed me up big time :D :D :D which I couldnt figure out until I had refitted the 3'rd shim was to measure the exhaust valve on the front left side WITHOUT the autodecomp bump in place. Make sure this is NOT interacting with the top of the bucket when measuring as you will find the valve clearance remains constant even if you whap in huge new shim (which I did) --- the autodecomp thing keeps pushing that bucket down no matter what shim you put in. Drove me nuts :):D :D until I took a flashlight and saw what I was doing then....DOH :D :D

Other than that enjoy....its real easy. Make sure you keep an eye on which bucket/shim goes where...mark up a piece of paper with the locations.

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Moly disulfide is an assembly lube used to cushion metal to metal mating parts until proper oil flow takes over the job. Use it liberally, as it will mix with the engine oil and disappear.

The first time I did this (I also split cases to change some gears) I used alot of assembly lube then tried to ride at a really hilly track. The end result was a slipping clutch. My recommendations would be to warm the bike up and change the oil again right away as I think the assembly lube has friction modifiers in it that are bad for the clutch. This may vary by brand.

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Everything checked out just fine. I do know one thing got to buy better thickness gauge.Thanks for all the good advice. :D:)

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New to TT looking for specific info. I want to know if 2002 wr426 and yz426 valve clearance specs are the same. I am doing yz cam timing on my wr and checking my valve clearance while i'm in there.

All my intake clearances are below specs I got from yZ manual. Would really appreciate the wr specs from someone.

WR426 in the process of many mods as we thread.

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