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-   -   Compression Too High? (https://atvconnection.com/forums/yamaha/340552-compression-too-high.html)

thomtwo 10-16-2011 11:36 AM

Compression Too High?
 
I did a head compression check on my '94 Kodiak 400, thinking this maybe a part of the Cold Start trouble.
It's been flooding out the plug and spraying fuel into the intake filter air box.

I have replaced the float needle and other carb parts with a K&L Carb Kit first. I've rechecked the float height twice. +.051"

After the engine is warm it starts fine, but cold, it only floods out.
Today, just to get it running I took my heat gun to the cylinder head and spark plug hole for about 15 minutes.
Then it started.


Here's the compression reading. The range has me very confused.
My Service Manual gives no info on what the Cold Pressure reading should be.

Cool Engine read 90 psi
Warmed up Engine read 170 psi

The Service Manual says the Warm Engine should be...
- (Standard)=131 psi
- (Minium) =105psi

It also says reading above maximum...
1) Inspect cylinder heads, valve surface, or piston crown for carbon deposits.

Man, am I confused and lost...

JLsparky7 10-17-2011 02:12 PM

170 is really high... Maybe its your gauge?


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