crossroads123
Seaman Apprentice
- Joined
- Feb 26, 2012
- Messages
- 47
Hello a couple of months ago I started a thread about my new to me, at the time, boat a 16 ft Alumacraft with a 1992 Mercury 40 hp motor. I was having starting issues and got some GREAT advise. I rebuilt the fuel pump and both carbs and followed the starting advise and she now starts and runs fine. I have completed the De-Carbonization proceedure and have taken a new compression check. I still have low compression readings 70psi on all four cylinders. I warmed the motor, WOT, and even shot oil into the cylinders with no improvement in the readings.
I don't pretend to be a boat mechanic, nor do I play one on tv, so I am turning to the experts. I would think if I am losing compression by the rings shooting oil into the cylinders would give some increase in sealing it did not. I would also think that if it were just ring wear there would at least some difference in the four readings, there's not 70 psi on all four. Now before you tell me my gauge is malfunctioning it's brand new and I verified it's reads with a second gauge. Is the something else that would cause all four cylinders to read so low??
The motor starts and runs fine, there is no excessive oil smoke, she doesn't foul plugs so I must turn to to the experts. Is there anything that can cause the low readings besides ring wear?? I would appreciate any help or advise. I will thank you in advance for your help.
I don't pretend to be a boat mechanic, nor do I play one on tv, so I am turning to the experts. I would think if I am losing compression by the rings shooting oil into the cylinders would give some increase in sealing it did not. I would also think that if it were just ring wear there would at least some difference in the four readings, there's not 70 psi on all four. Now before you tell me my gauge is malfunctioning it's brand new and I verified it's reads with a second gauge. Is the something else that would cause all four cylinders to read so low??
The motor starts and runs fine, there is no excessive oil smoke, she doesn't foul plugs so I must turn to to the experts. Is there anything that can cause the low readings besides ring wear?? I would appreciate any help or advise. I will thank you in advance for your help.
