KevinDonn1
New member
I have a Mercury 40 3cyl (1998 #0G719548) Over the winter I took the carbs out and gave them a thorough cleaning and adjustment. I also found an air/vacuum line that had eroded and replaced it. I put on a new fuel filter, new throttle cables and plugs. Using fresh non ethanol fuel.
Engine was bogging down at speed. Last week I had noticed that the primer ball would not stay hard after pumping it up before starting the engine and the engine was bogging down from time to time like it was not getting fuel. I thought this might be a bad check valve in the primer ball, so I replaced it. The engine started up much better after that and ran like a champ. When previously checking the fuel problem, I noticed a loose clamp between the fuel pump and the fuel filter where I had a small fuel leak. I replaced the clamps. No more leak there.
Today after being on the water all day, while heading back to the ramp I was running at full throttle for a couple of miles. The engine started bogging down. It sounded like it was starving for fuel. I throttled back to idle, and the engine struggled for a bit, then seemed to return to normal idle. I was able to get it back up to speed and run for a while. But it started bogging down again losing speed and horsepower.
In trying to figure out if is was a fuel issue, as it was at full throttle, I pulled up on the manual choke on the remote throttle, and it seemed to change the sound of the engine, but I still was losing horsepower severely. I dropped back to idle again, and it took a little longer to smooth out, but I was able to get it back up to speed.
When it bogged down, again sounding like it was starving for fuel, I pushed in the key to engage the enricher valve. I got a burst of horsepower, which to me confirmed I have a fuel issue. I never got the engine back up to full speed, but was able to keep pushing the key to open the enricher valve, which got me back to the boat ramp.
Also, during the day, while idling around and fishing, the engine did not seem to be running as smooth as it normally does.
So, the primer ball stayed hard, the engine ran a little rough all day while idling around and stalled a couple of times which is not normal, and I kept losing fuel at full throttle.
I'm assuming that I have either a fuel leak or I'm getting air in the line somewhere but I'm not sure where to begin diagnosing.
Please help.
Thanks,
Kevin
Engine was bogging down at speed. Last week I had noticed that the primer ball would not stay hard after pumping it up before starting the engine and the engine was bogging down from time to time like it was not getting fuel. I thought this might be a bad check valve in the primer ball, so I replaced it. The engine started up much better after that and ran like a champ. When previously checking the fuel problem, I noticed a loose clamp between the fuel pump and the fuel filter where I had a small fuel leak. I replaced the clamps. No more leak there.
Today after being on the water all day, while heading back to the ramp I was running at full throttle for a couple of miles. The engine started bogging down. It sounded like it was starving for fuel. I throttled back to idle, and the engine struggled for a bit, then seemed to return to normal idle. I was able to get it back up to speed and run for a while. But it started bogging down again losing speed and horsepower.
In trying to figure out if is was a fuel issue, as it was at full throttle, I pulled up on the manual choke on the remote throttle, and it seemed to change the sound of the engine, but I still was losing horsepower severely. I dropped back to idle again, and it took a little longer to smooth out, but I was able to get it back up to speed.
When it bogged down, again sounding like it was starving for fuel, I pushed in the key to engage the enricher valve. I got a burst of horsepower, which to me confirmed I have a fuel issue. I never got the engine back up to full speed, but was able to keep pushing the key to open the enricher valve, which got me back to the boat ramp.
Also, during the day, while idling around and fishing, the engine did not seem to be running as smooth as it normally does.
So, the primer ball stayed hard, the engine ran a little rough all day while idling around and stalled a couple of times which is not normal, and I kept losing fuel at full throttle.
I'm assuming that I have either a fuel leak or I'm getting air in the line somewhere but I'm not sure where to begin diagnosing.
Please help.
Thanks,
Kevin
