This is a new to new boat. 14ft skiff with a 1985/86ish Mariner 25hp. It’s a made in Japan model. My first outing the motor would not exceed 3000ish RPMs. Took it home cleaned the carb, fuel pump, new plugs. Second test run I had full power and ran perfect. 3rd run the boat ran great for about 60% of the time. Parts of the day it was full power and then half. Didn’t matter hot or cold could not duplicate it consistently. However ended the day running at full power. After this I replaced all fuel lines and fuel filter. Rebuilt the carb and adjusted the float level. Around this time frame I did a compression test and both cylinders were around 90 psi. Adjusted the timing based on the seloc manual. Everything seems to be in spec. Nothing I do makes any change on the water. Most recently I changed out the cdi module. Performed a spark test and I have a strong spark at 1/2inch. Checked the wires while running at night. No spark jumping between the wires.
While running pumping the primer bulb has no effect. Starts up with no issues. Idles fine without any issues and doesn’t smoke excessively.
Just checked the compression after a heavy decrab with sea foam. Warm and wet it’s reading around 80 on both. I used a endoscopic camera. The cylinder walls don’t look bad. Some small scoring on the side walls but I don't see any significant damage.
Coil is reading within spec and the stator as well per the manual.
Is compression my problem ?
