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compression test for 2003 CRF 450 (in PSI)

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What is the pressure range for the compression test on the 2003 CRF 450 (in PSI)?

Thanks,

Todd

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I ain't no pro wrench, but my leak down tester says something about how quickly it looses compression versus what PSI it holds - as the name implies "leak down".

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What is the pressure range for the compression test on the 2003 CRF 450 (in PSI)?

Thanks,

Todd

4 stroke compression tests are pretty hit or miss, as well as pretty worthless. Go look into a leak down tester if you are trying to do any type of mechanical engine diagnostic work......I work on 4 stroke engines all day and i use a compression tester so little i wouldn't even know what to tell you for a spec.

As for the leak down test, 10% leakage is pretty much the maximum you want to see on ANYTHING. And there are different ways to diagnose which component is fault if you have excessive leakage. Such as if you feel air coming up through the intake at the air box, you could have a leaking intake valve due to negative clearance or carbon buildup on the face, or its just plain messed up haha. Air escaping through the intake into the air box could also indicate worn piston rings. To confirm this try putting a SMALL amount of engine oil into the spark plug hole then turning the motor over a few times then perform the test again, if the test gets a better result, you know its your rings. You could also close off your crankcase breather line opposed to the engine oil trick but on some applications this is easier said than done.

Leak Down test for sure.

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You wont get a true reading because of the autodecompression cam.

only spec that I have ever seen is from a Kawi manual and it states 100 psi within 5 kicks at WOT.

You always perform a compression test at WOT and it doesnt matter how many kicks because it will peak no matter what. Kawasaki is silly i know i work on a lot of their stuff. Good product, literature is coming along slowly haha.

BTW disengage the auto decomp on your CRF and try to kick it. It wont move with my 175lb self standing on it.

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Disable the decompressor and if you can kick it over, its needs rebuilding.

or if he can , he can make alot of $ kicking 70 yard field goals:lol:

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