Hi everyone,
I’m seeking your advice on a motor that I have the opportunity to buy that needs some work. The motor is a 1990 Mercury Classic 40 hp (4-cylinder 2-stroke). Per the current owner, it runs but one cylinder has low compression and “is lightly scored”. I haven’t inspected it yet but he says the compression readings are 150 psi on 3 cylinders and 105 on the one with the scoring.
My questions to those knowledgeable in this area are:
1) if that really is “all” that is wrong with the motor, would I be able to tear down, hone, and re-ring just that one cylinder?
2) if I go that far, would you recommend new rings and honing on all cylinders, even though they have good compression now?
3) since the motor runs now, what would you look for during an inspection before buying and what would indicate other problems?
My understanding is that the scoring can be caused by a number of things. Including something very simple like a carb that needs cleaning.
The motor itself appears to be in otherwise great condition. With the power-trim, electric start, and overall size, I think it COULD be a really nice motor for my 16’ Alumacraft Backtroller.
Thanks in advance for your input and advice - always appreciated!
I’m seeking your advice on a motor that I have the opportunity to buy that needs some work. The motor is a 1990 Mercury Classic 40 hp (4-cylinder 2-stroke). Per the current owner, it runs but one cylinder has low compression and “is lightly scored”. I haven’t inspected it yet but he says the compression readings are 150 psi on 3 cylinders and 105 on the one with the scoring.
My questions to those knowledgeable in this area are:
1) if that really is “all” that is wrong with the motor, would I be able to tear down, hone, and re-ring just that one cylinder?
2) if I go that far, would you recommend new rings and honing on all cylinders, even though they have good compression now?
3) since the motor runs now, what would you look for during an inspection before buying and what would indicate other problems?
My understanding is that the scoring can be caused by a number of things. Including something very simple like a carb that needs cleaning.
The motor itself appears to be in otherwise great condition. With the power-trim, electric start, and overall size, I think it COULD be a really nice motor for my 16’ Alumacraft Backtroller.
Thanks in advance for your input and advice - always appreciated!
