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djo269

lots of questions about my new 450

10 posts in this topic

I just bought a 2003 yamaha yz450f. I am getting the service manual in a week or so from the guy and the rest of the parts. Since I dont have the manual I was wondering if someone could tell me the specs on the valves. I plan to check them today but need to know what are the limits. What weight of fork oil is stock, the Suspension 01? What is the proper method to check motor oil, warm engine up then check or check while its cold? The guy said he used the yamalube semi-synthetic oil, if I switch to the 20w-40 would that be ok? I heard that if you go synthetic you cant go back to straight weight, is that correct? I noticed that there is like somekind of paint sprayed on the swingarm closer to the engine, makes it appear to have some kind of coating sprayed on: what is this and is it meant to be there? What are some internal engine signs of neglect or abuse to the bike? Is the method of changing fork seals similiar to the method used on a 02 yz250f? I have alot more questions but I'll wait to hit them up later! thanx alot 4 ur help

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I just bought a 2003 yamaha yz450f. I am getting the service manual in a week or so from the guy and the rest of the parts. Since I dont have the manual I was wondering if someone could tell me the specs on the valves. I plan to check them today but need to know what are the limits.
.10-.15mm Intake; .20-.25 Exhaust
What weight of fork oil is stock, the Suspension 01?
5wt. I like Mobil 1 Dexron III ATF better.
What is the proper method to check motor oil, warm engine up then check or check while its cold?
The engine has to have been run for at least a minute for an oil level check to mean anything. It runs back into the crankcasae (very slowly) as it sits.
The guy said he used the yamalube semi-synthetic oil, if I switch to the 20w-40 would that be ok?
The viscosity is fine, but I personally don't like Yamalube.
I heard that if you go synthetic you cant go back to straight weight, is that correct?
Total BS.
What are some internal engine signs of neglect or abuse to the bike?
Dirt. Dirty oil. Crap piled up around the oil filter. Scored cam bearing surfaces. Hammer marks.
Is the method of changing fork seals similiar to the method used on a 02 yz250f?
Exactly the same.
I have alot more questions but I'll wait to hit them up later! thanx alot 4 ur help
The anticipation is killing me. :applause:

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I checked my valves and all were within spec except the middle intake which I could fit a .08mm but not a .10mm. Should I go ahead and shim the middle intake back in spec or just go and ride some more? What are hammer marks and where would you see them at? What is the total amount of motor oil you can add at an oil change for this bike? thanx

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lol hammer marks was a joke, about beating the living hell out of your bike.

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I checked my valves and all were within spec except the middle intake which I could fit a .08mm but not a .10mm. Should I go ahead and shim the middle intake back in spec or just go and ride some more?
Shim it now. It will last longer. Don't get involved in trying to optimize the rest of them; if they are in spec, they are in spec. However, shims may not always be available when you want them, so you might want to take the time to write down which shims are on which valves while you're in there. Shims for a CRF450 will interchange with yours, so if the Blue dealer doesn't have one, the Red one might. If you can't get one, you should be able to ride it once more while the part comes in, if you just can't wait.
lol hammer marks was a joke, about beating the living hell out of your bike.
That's what it was about, alright.

But it wasn't a joke.

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I have the soft copy of this manual if you need it.

However, it's 28 megs so it would need to be uploaded somewhere.

Let me know.

DaveJ

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I think grayracer513 should be the yz450f forum moderator. thanks to everyone that helps others and a special thanks to grayracer513. :applause:

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