Volvo

[capt.jim]

We have changed all filters, fuel and pumps. The engine runs good except one quert.

We troll at 700 rpm for about 1 to 2 hrs and we start to power up and it won't go pass 1200rpm for at least 15 to 20 mins. Then she runs good again until we troll the next time and the same thing happens..

[boatman61]

My experience is they get unhappy at less than 900rpm... try trolling under sail..

[GordMay]

Greetings and welcome aboard the CF, capt.jim.

[rwidman]

Originally Posted by capt.jim

We have changed all filters, fuel and pumps. The engine runs good except one quert.

We troll at 700 rpm for about 1 to 2 hrs and we start to power up and it won't go pass 1200rpm for at least 15 to 20 mins. Then she runs good again until we troll the next time and the same thing happens..

Is this a gasoline or diesel engine? What model engine?

Did this problem start after you changed the filters, fuel and pumps or was it doing this before you changed the filters, fuel and pumps? If it was doing this before you changed all the filters, fuel and pumps, when did it start and were there any maintenance procedures or unusual circumstances just before it started doing this?

Assuming that you bring the throttle up to the high speed position after trolling and it doesn't go fast, are there any unusual symptoms, vibration, noise or smoke during this period? How about the engine temperature?

Are there and unusual noises or vibrations when the engine eventually starts to run at the normal speed? Does it speed up gradually or all of a sudden?

If you stop the engine and restart it, will it run at the normal speed or still slow?