yamaha concern

I have had a few and they had that number with out issue. Yamaha's love to get carboned up!! That's why they all say to use carbon free when you fill up.
I used a Sea foam treatment on one of mine, and saw the compression go up 10 PSI across the board. It would not worry me if the rest of the motor checks out.
Good Luck
 
smokeonthewater said:
also understand that a compression test is to be performed on a warm engine at WOT
Click to expand...

Sorry Smoke, I have to disagree. How can you do a compression test at WOT? Warm engine yes, ... I totally agree, but I don't recommend trying to do a test on an engine running around 5000 rpm.

First, warm the engine up, You'll also need to disable your ignition system. You're going to need to crank the starter to turn the engine over but you don't want it to actually start. Then unscrew a plug and screw your adapter into the vacant hole, then screw in the hose leading to your gage into the adaptor. Turn the engine over a few revolutions... that's enough to get an accurate reading. Record the reading for that cylinder, then repeat on each of the other cylinders. They should all be within about 10 lbs of each other. That's all there is to it.
 
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i think he means with the throttle in the wide open position, not actually running. that would be a little tricky..
 
check your gauge, I've got three different gauges that read 30 psi difference between them, I've a got a selling gauge:zip:, buying gauge:sly:, and one that reads correctly. Normally if they all read close to each other, thats all you need. I did an engine check out for a customer buying a boat, compresion on both engines came well withing spec around 125 psi. He called me after taking delivery all pissed off because his mechanic said both engines were worn out, he said his gauge read 80 psi. I told him to get another gauge and another mechanic. He called back two days later and apologzed to me, he took it to anotehr mechanic and it checked out OK
 
Whats wrong with thumbin the hole?? My right thumb is accurate to about 3psi. My left thumb however, is off about 6psi:beer:
 
The 98 wouldn't scare me as long as it's even but I would use it as a bargaining chip I my favor.

I think the 1992 still had the plain steel shift rod. I know the 225HP's did but not sure on the 250's.

Quick check on part numbers shows 61a-44120-21-00 for '92 and 61a-44120-22-00 for '94 so I would think it was steel.

If it hasn't been replaced already then check it out as best you can.
 
They started using the SS rods in 1994 in the saltwater series, Before that they are steel and if not replaced yet it will need it! Winch means removing the power head, which can be a hard job if its to corroded? I had one done on a new to me motor and the guy that I bought it from was a Marine Mech so he did it. BS had to do one and he did it with his father with out problems.
But it was 10 years ago for us and they were not as rotted as today's would be. Just look at it well but that might not be good enough, I was looking for it when I bought mine and saw nothing till it broke.
 
THERE used to be a guy on ebay that manufactered a 2 piece shift rod for yamaha ,, it did not require removing the power head and was a pretty easey fix
 
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