timjet
Guru
- Joined
- Apr 9, 2009
- Messages
- 1,920
I've had my boat a year now and am just starting to use it after several maintenance issues. When I purchased the boat I knew we had a fuel quality problem so before purchase I had the aux tank fuel professionally cleaned. To get the boat home I added 50 gal of fuel to the aux tank bringing it up to about 60 gal and left the tank selector valves in the aux position. I used about 10 gal to get home leaving about 50 or so gal left.
The boat has 3 tanks, the aforementioned aux tank and the L and R tank. I had those tanks cleaned and filled them up with new fuel and left what was remaining in the aux tank. I repositioned the tank selector valves so the engines would burn out of their respective tanks and they have remained in that position until today.
After about 20 hours use, I refilled the main tanks and noticed the L tank took about 30% more fuel. I did not add fuel to the aux tank. Again after 20 hrs of use I refilled with the same results. I did not check the aux tank capacity.
I took the boat out today to test a newly installed impeller and also to run some fuel from the aux tank to make sure the fuel quality was OK. I ran fuel from the aux tank only to the starboard engine, not wanting to press my luck. Everything ran fine. When I got back I checked the fuel gauges and to my surprise the aux tank gauge showed full and the L and R tank gauges showed just slightly above 3/4 full. I thought that perhaps the aux tank fuel sending unit had failed since I had not added fuel to the aux tank in over a year and it had about 50 gal last time I checked.
I pulled the sending unit and indeed the aux tank was full, in fact too full. I pumped about 15 gal out of the aux and into the L tank.
So, whats going on. Obviously the L engine is not burning 30% more fuel, it's somehow putting the return fuel into the aux tank.
The fuel transfer valves are of the ganged variety in which both the return and feed are on one handle. The handle has a square groove that fits a square stem on the valve. If it was positioned incorrectly it would be obvious because the markings would not line up with the handle. It is a 3 position valve, Off - Aux - L or R as appropiate. This allows the aux tank to feed either engine or the L or R tank to feed it's respective engine only.
There are 6 ports on the transfer valve. 3 for the feed and 3 for the return. The 3 ports closest to the handle are slightly larger than the other 3 behind them. One of the larger ports has a hose attached that goes to the Racor filter. I cannot tell where the other 5 hoses go.
Where do I start figuring this out??
The boat has 3 tanks, the aforementioned aux tank and the L and R tank. I had those tanks cleaned and filled them up with new fuel and left what was remaining in the aux tank. I repositioned the tank selector valves so the engines would burn out of their respective tanks and they have remained in that position until today.
After about 20 hours use, I refilled the main tanks and noticed the L tank took about 30% more fuel. I did not add fuel to the aux tank. Again after 20 hrs of use I refilled with the same results. I did not check the aux tank capacity.
I took the boat out today to test a newly installed impeller and also to run some fuel from the aux tank to make sure the fuel quality was OK. I ran fuel from the aux tank only to the starboard engine, not wanting to press my luck. Everything ran fine. When I got back I checked the fuel gauges and to my surprise the aux tank gauge showed full and the L and R tank gauges showed just slightly above 3/4 full. I thought that perhaps the aux tank fuel sending unit had failed since I had not added fuel to the aux tank in over a year and it had about 50 gal last time I checked.
I pulled the sending unit and indeed the aux tank was full, in fact too full. I pumped about 15 gal out of the aux and into the L tank.
So, whats going on. Obviously the L engine is not burning 30% more fuel, it's somehow putting the return fuel into the aux tank.
The fuel transfer valves are of the ganged variety in which both the return and feed are on one handle. The handle has a square groove that fits a square stem on the valve. If it was positioned incorrectly it would be obvious because the markings would not line up with the handle. It is a 3 position valve, Off - Aux - L or R as appropiate. This allows the aux tank to feed either engine or the L or R tank to feed it's respective engine only.
There are 6 ports on the transfer valve. 3 for the feed and 3 for the return. The 3 ports closest to the handle are slightly larger than the other 3 behind them. One of the larger ports has a hose attached that goes to the Racor filter. I cannot tell where the other 5 hoses go.
Where do I start figuring this out??