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hi everybody

newbie to valve adjustments...07 450

18 posts in this topic

hey...so I decided to check my valve clearances today, I believe I have about 25-30 hours on it.

so both of my exhaust pass a .203mm

my center, and right intakes pass a .102mm

but my left wont...the next size down I have is a .076mm, and that passes...

Im going to get another set of metric feelers, but I believe I will have to shim these. Is it common to have just one intake out? I understand that all of my valves are at the tight end of the range...so should I shim all of them, or just the one intake?

this is the first 4 stroke Ive worked on, and Im kinda lost on how to adjust the valves..but would like to do it myself, and can't really afford to take it in...any help? maybe some first steps to send me in the right direction?

gray...you seem to know your sh!t, you think I could leech some knowledge off of you?

thanks for everybodys time!!!

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Yes. Point of fact is that it is very likely that where you found them is precisely where they were originally set by the factory, except for the one tight one that probably settled into the seat a little. Bear in mind that the variance that you have from spec is .00094" IF the clearance actually is .076mm. Bear that in mind when you determine the current shim size. You only need .03 to be in compliance, so if you find, for example, a 188*, you can bring it into spec with a 185.

* The factory has access to shims in .01 mm increments for the initial head setup. Don't be surprised to find odd numbers that aren't listed in the manual.

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ok....thanks a load! like I said this is my first time working with a 4 stroke, so all this shim and clearance business is new...

where is the best place to get shims? Ive seen the hot cams kit that comes with all sorts of them..but isnt that like $90?

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You only need one. It should cost $6-7 at a dealer. No more often than a YZ450 needs a valve adjustment, there's no reason whatsoever to run out and blow $90 on a kit half filled with shims no YZ can even use (and missing several sizes that you theoretically could use).

Get the shim from any Yamaha , Honda , Kawasaki , or Suzuki dealer. All the MX 450's take the same series of 9.48 mm diameter shims, and come in more or less the same range of sizes. The Honda shop will be somewhat more likely to have them in stock, so if you strike out at the Blue House, go straight to the Red House.

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yeah..I just called the red/blue house that I worked as garbage kid for about a month...they carry em all in stock, so hurray!!! Ill probably get into this endeavor tomorrow night..although it seems that it isnt too complicated...now that I read through the book and everything.

oh...another quick question. for removing the buckets..or as the manual refers to em as "valve lifters" is there any trick to it? or do they pretty much lift up outta the head with your fingers?

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They might come out with your fingers, but they may not. You can use a pair of needle nose, carefully. If they are still stubborn, cut out a little piece of an old inner tube to put between the lifter and pliers to improve your grip.

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They might come out with your fingers, but they may not. You can use a pair of needle nose, carefully. If they are still stubborn, cut out a little piece of an old inner tube to put between the lifter and pliers to improve your grip.

Perhaps I am speaking way out of place as I have never even seen a 450's top end, but on my 01 426 a magnet, like a mechanic's magnetic pickup tool is the simplest and best way to remove the lifters. This also holds the shim in place so you don't lose it and the lifter and shim come out in one shot, together. Hopefully you can use that tip on the 450s too and I am not just wasting thread space!

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The shims like to come out with the lifters most of the time, anyway. They stick to the oil film ont the bottom of the bucket.

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yeah..I just pulled the intake cam and the lifter...I have a 182 in there, and im in the .05-.09 range, so the little chart says to put a 175 in it.

also...the cam chain tensioner only has two copper washers, correct? one on one of the mounting bolts, and then the cap bolt, right?

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ok..I thought there was three..and that I lost one.

guess I just need to spend less time round those fuel fumes :banghead:

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question...what about this molybdenum disulfide oil the manual speaks of? what is it, where can i get it, and do I really need to use it? It says to place is on the cam and threads for the bolts holding the cam cap in place...I asked my father about the oil, and he said its mostly used when first building new engines, and that I might not need it...so is that the case?

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Wha'd'ya know! Dad's right. Probably not the first time, either.

It's "assembly lube", get it at an auto parts store, and no, the only oil you need is the oil you run it with. Oil up all the part with it and go.

What you absolutely do need is a torque wrench. The caps must fully seat just by pushing them in place with your hands, and/or tapping gently with a screwdriver butt. DO NOT draw them down with the bolts. If they're assembled right, they go together. Then, torque them in sequence as shown, and in 3 steps up to the spec. Under no circumstances go any tighter than 7.2 ft/lb (86 in/lb). In fact, I always use 6.25 ft/lb (75 in/lb) on my bikes, because frankly, that's tight enough.

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cool...thanks a load. I called the service department about it, and the guy said to use just any assembly lube would work, and just put a little bit on the journals and the threads...So I got some "assembly lube with moly" at the local napa..

and I did push the caps in place with my hands...and then torqued them to 7 ft/lbs.

thanks for everything!

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You only need one. It should cost $6-7 at a dealer. No more often than a YZ450 needs a valve adjustment, there's no reason whatsoever to run out and blow $90 on a kit half filled with shims no YZ can even use (and missing several sizes that you theoretically could use).

Get the shim from any Yamaha , Honda , Kawasaki , or Suzuki dealer. All the MX 450's take the same series of 9.48 mm diameter shims, and come in more or less the same range of sizes. The Honda shop will be somewhat more likely to have them in stock, so if you strike out at the Blue House, go straight to the Red House.

:banghead:

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