berth control
New Member
1985 170 mercruiser engine. Carb. and mechanical fuel pump. Recently replaced plugs, cap, rotor, wires, adjusted timing, cleaned fuel filter in carb. and cleaned the carb. Checked compression last week, all were at about 120, so good.
I was cruising back from a trip yesterday when about 20 miles in I started losing power on the stbd. engine. It went from 3500 (my normal cruise) down to about 3000, 2900, 2800, I gave it more throttle to adjust and it did not do much. Temp. was good, oil pressure good, other engine running fine. Pretty soon I could not maintain plane and had to come down to idle. Then the engine idled in neutral for a bit until I went to rev it up and it died. Would fire but not restart. At one point I got it to start up and fast idle at about 3,000rpm's, but would not idle or let me put it in gear.
I got back to the dock and backed into my slip on one engine (pretty impressed with myself for that, I was better than my neighbor with twins:grin. I started to tell the guys at the dock about what happened and went to show them what the engine was doing. It started right up and seemed to run fine. I could not put much load on it since I was at the slip, but it would rev up good and I could idle it and put it in gear no prob.
I think the mechanical fuel pump is weak and when it gets warm it does not pump like it should. I took the fuel line off the carb and cranked the motor over. It pumps a lot of volume, but very little pressure (I can easily stop the flow of fuel with my finger over the line).
Any ideas or opinions before I slap on a new fuel pump and rebuild the carb this week?
I was cruising back from a trip yesterday when about 20 miles in I started losing power on the stbd. engine. It went from 3500 (my normal cruise) down to about 3000, 2900, 2800, I gave it more throttle to adjust and it did not do much. Temp. was good, oil pressure good, other engine running fine. Pretty soon I could not maintain plane and had to come down to idle. Then the engine idled in neutral for a bit until I went to rev it up and it died. Would fire but not restart. At one point I got it to start up and fast idle at about 3,000rpm's, but would not idle or let me put it in gear.
I got back to the dock and backed into my slip on one engine (pretty impressed with myself for that, I was better than my neighbor with twins:grin. I started to tell the guys at the dock about what happened and went to show them what the engine was doing. It started right up and seemed to run fine. I could not put much load on it since I was at the slip, but it would rev up good and I could idle it and put it in gear no prob.
I think the mechanical fuel pump is weak and when it gets warm it does not pump like it should. I took the fuel line off the carb and cranked the motor over. It pumps a lot of volume, but very little pressure (I can easily stop the flow of fuel with my finger over the line).
Any ideas or opinions before I slap on a new fuel pump and rebuild the carb this week?
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