2003 Glastron GX185
Volvo Penta 4.3 GL-C
146 hours on engine.
Fuel tank full
Just got the boat and put it in the water for the first time this weekend.
Sat. Spent most of the day on the hook but ran at various speeds for a couple of hours with no problem.
Sun. Ran for about an hour at approx 3000 RPM. Stopped for maybe 30 minutes then headed back. About 15 minutes into the trip the engine started "surging" and losing power. I throttled back to idle and it ran fine. Slowly increased throttle and it ran fine until I picked up speed again. (don't have the RPM numbers as I was too frazzled at the time. Two KM off shore and several KM from the nearest marina and my new boat was acting up)
I was able to limp home at slow speed. I tried speeding up a couple of times and the surging would always return.
I'm no mechanic and I'm a first time boat owner but my first thought was that the fuel filter was partially plugged, flowing enough gas for low speed operation but not enough for high speed.
Unrelated I'm sure, but my gas gauge was stuck at FULL, so I went to fuel up just in case. I knew I couldn't have burned a whole tank (110 litres) but I wanted to know how much I'd used. When I opened the fuel cap there was a loud sound of inrushing air. The gas tank was under a vacuum.
So now I'm thinking that's the problem. When I look at my gas filler assembly it has two lines going to it from the tank, the fuel fill line and the tank vent line. However, the gas cap itself has no vent so when it is screwed in tight it seems there's no way for the gas tank to vent.
The gas cap is not connected to the little safety chain either which makes me wonder if the original was lost and the wrong replacement was used. The gas fill assembly is a Perko FIG 540
I put the boat back in the water Monday and ran it for a long time at >3000 RPM and for a while at full throttle. It worked fine all day. When I got back I opened the gas cap and heard air rush in again but not as much as before.
Just curious what you guys think. Do you think the tank not venting properly is my problem?
My wife was freaked out by this incident so I think the boat will be going into the shop to get a new gas filter and anti-syphon valve but I think all it really needs is the correct vented gas cap.
Appreciate any input.
Volvo Penta 4.3 GL-C
146 hours on engine.
Fuel tank full
Just got the boat and put it in the water for the first time this weekend.
Sat. Spent most of the day on the hook but ran at various speeds for a couple of hours with no problem.
Sun. Ran for about an hour at approx 3000 RPM. Stopped for maybe 30 minutes then headed back. About 15 minutes into the trip the engine started "surging" and losing power. I throttled back to idle and it ran fine. Slowly increased throttle and it ran fine until I picked up speed again. (don't have the RPM numbers as I was too frazzled at the time. Two KM off shore and several KM from the nearest marina and my new boat was acting up)
I was able to limp home at slow speed. I tried speeding up a couple of times and the surging would always return.
I'm no mechanic and I'm a first time boat owner but my first thought was that the fuel filter was partially plugged, flowing enough gas for low speed operation but not enough for high speed.
Unrelated I'm sure, but my gas gauge was stuck at FULL, so I went to fuel up just in case. I knew I couldn't have burned a whole tank (110 litres) but I wanted to know how much I'd used. When I opened the fuel cap there was a loud sound of inrushing air. The gas tank was under a vacuum.
So now I'm thinking that's the problem. When I look at my gas filler assembly it has two lines going to it from the tank, the fuel fill line and the tank vent line. However, the gas cap itself has no vent so when it is screwed in tight it seems there's no way for the gas tank to vent.
The gas cap is not connected to the little safety chain either which makes me wonder if the original was lost and the wrong replacement was used. The gas fill assembly is a Perko FIG 540
I put the boat back in the water Monday and ran it for a long time at >3000 RPM and for a while at full throttle. It worked fine all day. When I got back I opened the gas cap and heard air rush in again but not as much as before.
Just curious what you guys think. Do you think the tank not venting properly is my problem?
My wife was freaked out by this incident so I think the boat will be going into the shop to get a new gas filter and anti-syphon valve but I think all it really needs is the correct vented gas cap.
Appreciate any input.
