1970 Mercruiser 140 3.0 carbon exhaust and loss of power

[primo3236]

Hi all, 1970 Mercruiser 140 3.0 I/O

I have been running well for a few days when suddenly after a fill up I began bogging and losing power. Also noticed black carbon from the exhaust.

Pulled the boat from the water, cleared the gas in fear that I had gotten a bad batch of fuel. Started back up with new gas and filter,same issue.

I then noticed a large un-uniform tare in my exhaust bellows, could this have been causing my issues, or should I look at testing the fuel pump?

I ask because the bellows did not appear to have any other holes/vents in it.

Thank you.

 

[alldodge]

Hi all, 1970 Mercruiser 140 3.0 I/O

I have been running well for a few days when suddenly after a fill up I began bogging and losing power. Also noticed black carbon from the exhaust.

Pulled the boat from the water, cleared the gas in fear that I had gotten a bad batch of fuel. Started back up with new gas and filter,same issue.

I then noticed a large un-uniform tare in my exhaust bellows, could this have been causing my issues, or should I look at testing the fuel pump?

I ask because the bellows did not appear to have any other holes/vents in it.

Thank you.

You probably got some crud in the metering channels of the carb and it needs a good cleaning and rebuild. You could check you fuel pump pressure while your at it 4-7 psi. The tear in the exhaust bellows is not bad and would not cause your issue, just make it a bit louder.

 

[primo3236]

Thats going to be a tough pill to swallow. The carb is brand new with only 1 tank of gas through it...

 

[airshot]

Can still pick up crap in the fuel. Do you have a fuel water/seperator/filter inline on the fuel line? Make sure the choke plate is not stuck closed. Crap in the fuel could also cause the float to stick if the filters did not pick it out.