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minimum compression pressure refer below.
(reference data) compression pressure 101.5 PSI
(minimum) compression pressure 75.4 PSI
it's model Yamaha 200AET (2,596 cc) v6.
have a nice day.
They don't really post the comp. figures because the results can vary so much with the
equipment and the procedures.
The important thing is the results are all within 5% of each other.
My gauge on a 200 Yam gets 150# on a healthy motor.
A Harbor Freight gauge gets 110# some read worse??
Last week did a test on a 2 2005 200 hp
One motor had 150 all 6
The other had 130 155 140 150 150 150
Get a good gauge and look on U tube for directions.
What results did you get?
If all 6 are the same???
The Yams I tested are 2 stroke v-6's.
What gauge you using? a screw in or the one you shove in the hole?
Harbor freight tools are junk.
Your results: 1st test. 3 at 94 3 at 87 that's 6-7% difference.
That's acceptable.
Do you use Yamaha's ring free?
Or use a decarb?
Yam oil is supposed to run best and not carbon up.
I bought a snake camera for my Android phone. $11
Works pretty good for checking the cylinder walls.
Best to do it under a cover or after dark.
That's very possible, the early OMC had motors with lower comp #s too.
I've found if you run in salt water (even a little) you should change the head gaskets every couple of years.
The salt residue builds up around the hottest spots and can lead to gasket failure.