Last year I blew a piston in the motor and replaced it, it ran ok but then more problems started. Then I started having a shuttering and lose of power issue that I never got resolved last year. I didn't have time to work on it this year so I took it a mechanic. He said he replaced the fuel filter and that fixed it. I laughed and said ok. I took it out and nope still doing the same thing. So I tied up at the marina and spoke with the mechanic, he said it must be crud in the tank clogging the pickup. So I looked in the tank it it looked clean and shiny.
Today I hooked up a 20gal tank straight to the primer bulb and got the same result. I then bypassed the small plastic fuel filter on the engine and same result. Full throttle got me 2000RPM and at lower throttles I would get shuttering, sometimes a bit violent. To me it seemed like it was firing on the wrong stroke. Heres a short video of it running with the carb cover off. What are your guys thought?
1996 Mercury 225 issues - YouTube
Compression
80 (piston I replaced last year, expected this)
95
100
95
95
95
TPS is set correctly, also as far as I can tell so is the crank sensor and the temp sensor if working right. If I am reading the timing right I'm getting around 8 degrees at idle and as increase RPM in neutral the timing is retarding, which doesn't make any sense.
1996 Mercury 225 issues - YouTube
Today I hooked up a 20gal tank straight to the primer bulb and got the same result. I then bypassed the small plastic fuel filter on the engine and same result. Full throttle got me 2000RPM and at lower throttles I would get shuttering, sometimes a bit violent. To me it seemed like it was firing on the wrong stroke. Heres a short video of it running with the carb cover off. What are your guys thought?
1996 Mercury 225 issues - YouTube
Compression
80 (piston I replaced last year, expected this)
95
100
95
95
95
TPS is set correctly, also as far as I can tell so is the crank sensor and the temp sensor if working right. If I am reading the timing right I'm getting around 8 degrees at idle and as increase RPM in neutral the timing is retarding, which doesn't make any sense.
1996 Mercury 225 issues - YouTube