jdavenport
New member
"I inherited a boat and motor
"I inherited a boat and motor from my Dad recently. The motor is a 1989 Mercury Classic 40 4 cylinder. I've had it out the past 2 days and here is what it is doing.
The low speed idle is very rough, seems rich to me, but that is not the main problem.
When I took off from the dock the engine runs up good and puts me right on plane. After 2-4 minutes of running, it starts dropping a cylinder or two intermittantly and I can't get it to run over 3K rpm. I am very familiar with 2-strokes and this does not sound like a lean bog or rich load up. It's dropping cylinder(s). Lower the throttle below 3K and it fires on all 4.
About the same time it started behaving this way my Depthfinder started giving an input voltage too high alarm at anything much above idle.
so what gives? Seems like something electrical has gone bad in the engine. Voltage reg? If it failed would it cause issues with the ignition?"
"I inherited a boat and motor from my Dad recently. The motor is a 1989 Mercury Classic 40 4 cylinder. I've had it out the past 2 days and here is what it is doing.
The low speed idle is very rough, seems rich to me, but that is not the main problem.
When I took off from the dock the engine runs up good and puts me right on plane. After 2-4 minutes of running, it starts dropping a cylinder or two intermittantly and I can't get it to run over 3K rpm. I am very familiar with 2-strokes and this does not sound like a lean bog or rich load up. It's dropping cylinder(s). Lower the throttle below 3K and it fires on all 4.
About the same time it started behaving this way my Depthfinder started giving an input voltage too high alarm at anything much above idle.
so what gives? Seems like something electrical has gone bad in the engine. Voltage reg? If it failed would it cause issues with the ignition?"
