Volvo penta ad31 power

[stelican]

A very long overdue update to the above. I've used the boat occasionally with the issue present and then took it out of the water to do some repairs, antifouling etc. I put it back in the water only last week, determined to finally get to the bottom of my "low power" issue. I still felt sure it was fuel related, either volume or pressure. So today, as a step in that direction, I put a priming bulb on the fuel line, between the main fuel filter/water separator and the lift pump. I primed the filter and squeezed the primer bulb until it became hard, as per normal function. I fired her up and took off down the bay, hoping to see any sort of improvement over my usual 8mph max, thus assuring me that I was heading in the right direction. I throttled up and the speed increased, with the revs passing my usual 2k RPM, and continued to climb along with speed! I heard and felt the turbo kicking in, which had never happened before, as I never got to the required 2.5k RPM. I continued accelerating under I eased off at 22.5mph! This was at about 3kRPM. To say I was blown away would be an understatement. So now a more permanent fix is on the cards, by replacing the primer bulb with an electric fuel pump and an inlíne non return valve. I discovered a lot of owners on here were experiencing the same problem with low power and maybe this might prove to be a very cheap and simple cure. Happy days!

Well I'm biggered!

 

[Plum]

A very long overdue update to the above. I've used the boat occasionally with the issue present and then took it out of the water to do some repairs, antifouling etc. I put it back in the water only last week, determined to finally get to the bottom of my "low power" issue. I still felt sure it was fuel related, either volume or pressure. So today, as a step in that direction, I put a priming bulb on the fuel line, between the main fuel filter/water separator and the lift pump. I primed the filter and squeezed the primer bulb until it became hard, as per normal function. I fired her up and took off down the bay, hoping to see any sort of improvement over my usual 8mph max, thus assuring me that I was heading in the right direction. I throttled up and the speed increased, with the revs passing my usual 2k RPM, and continued to climb along with speed! I heard and felt the turbo kicking in, which had never happened before, as I never got to the required 2.5k RPM. I continued accelerating under I eased off at 22.5mph! This was at about 3kRPM. To say I was blown away would be an understatement. So now a more permanent fix is on the cards, by replacing the primer bulb with an electric fuel pump and an inlíne non return valve. I discovered a lot of owners on here were experiencing the same problem with low power and maybe this might prove to be a very cheap and simple cure. Happy days!

Wow, such a dramatic improvement. Before doing anything else, I would remove that primer bulb and repeat the sea trial, then put it back and trial again. This would help to prove that there is not another factor.

 

[sogood]

I know what you mean, but I had used the boat a few days before with the problem present. The modification I did was the only change made since then and the results speak for themselves. I think I'm safe enough to proceed with fitting the fuel pump. Watch this space!