sinkerfish
New member
"I have a 1979 Volvo AQD401A e
"I have a 1979 Volvo AQD401A engine matched with a 280B O/D duo prop that will not reach max RPM of 3600. If I correctly recall the prop size is A4. However she ran fine before so I don't believe the prop size to be a problem
Before sitting for 2 years she used to reach the max but now will only make it 24 - 2600 with a full load, 2800 light load and 3000 - 3200RPM with just me and 1/3 of a tank of fuel.
As mentioned above she sat for 2 years untouched. Before that she always got up to 3600 RPMs and would do at least 20MPH fully loaded. After sitting once I got her on the water with a full load she topped out at 2600 on a smooth sea and wouldn't go over 10MPH. Sitting in the driveway she revs up as high as I want her too.
I found a lot of debris in my fuel filter/water separator. Since then I have flushed the fuel tank, strained what fuel was there. Changed all fuel filters, cleaned the screen in the fuel pump, air filter, crank case ventilation filter, belts, oil and filter.
Not done yet is checking my throttle cable for slippage, fuel injection pump and lines leading to and from, or for a spun prop (duo prop).
I'm not sure if I am on the right track or not. Am I? Even if I am what are some other causes that would cause a loss of RPMs. Especially would need help with the fuel injection pump.
Thank you in advance"
"I have a 1979 Volvo AQD401A engine matched with a 280B O/D duo prop that will not reach max RPM of 3600. If I correctly recall the prop size is A4. However she ran fine before so I don't believe the prop size to be a problem
Before sitting for 2 years she used to reach the max but now will only make it 24 - 2600 with a full load, 2800 light load and 3000 - 3200RPM with just me and 1/3 of a tank of fuel.
As mentioned above she sat for 2 years untouched. Before that she always got up to 3600 RPMs and would do at least 20MPH fully loaded. After sitting once I got her on the water with a full load she topped out at 2600 on a smooth sea and wouldn't go over 10MPH. Sitting in the driveway she revs up as high as I want her too.
I found a lot of debris in my fuel filter/water separator. Since then I have flushed the fuel tank, strained what fuel was there. Changed all fuel filters, cleaned the screen in the fuel pump, air filter, crank case ventilation filter, belts, oil and filter.
Not done yet is checking my throttle cable for slippage, fuel injection pump and lines leading to and from, or for a spun prop (duo prop).
I'm not sure if I am on the right track or not. Am I? Even if I am what are some other causes that would cause a loss of RPMs. Especially would need help with the fuel injection pump.
Thank you in advance"
