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Compression on a 25hp Triple 1998 2 stroke

B

bigtime_mcalpine

Regular Contributor
I’ve got two of these motors. The first gas compression at 135psi. The second motor has 125psi across all thre cylinders. Im thinking that number is still fine. Do any of you disagree?
 
Boobie said:
They're fine. How they run ??
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Thanks! Well the 35 runs like a top! As for the 25, i ran it last season and it ran marvellously. I sold it last week to a poor fella who drove 5 hours to get here and back to his place only to get feedback from his mechanic that a) compression was low, b) it would not hold RPM’s at speed and c) mech said it needed a new CDI. I told him I would take it back. So, it’s back in my drive. I ran it for 30min checking to make sure all cylinders are firing - check. I checked compression and the cylinder that WAS 130 was now 125 (other two were 125). I check head temp and it seemed to be running too hot. Took thermostat off to find that the rubber bits inside looks swollen and displaced. So, I took the thermostat from my 35 and put it on and it did seem to run cooler. I then tested best I could with motor in a large barrel to see what med rpm’s looked like and the thing seems fine. Would prefer to run it on a boat before offloading but the darned bracket is bolt-on and I’m not about to drill holes in my transom just to test…I’m thinking that maybe it was overheating and losing it’s RPM’s…
 
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