I was out about a month ago when my motor started to miss on my 2004 H41AC. The boat would run at around 1200 RPM, but when pushed up to 2000 RPM, which is my usual cruising range, it would bog and start to die. I immediately thought the fuel filter/water trap must be clogged or fouled. So pulled up and pulled off the large bulkhead mounted fuel filter and water trap - It was absolutely clean and free from water or crap. I did not bother checking the engine fuel filter, (small one on the block) as if the large filter had nothing in it there was no way that the small filter should be fouled.
So I then went around the engine looking for loose hose clamps thinking that perhaps I was dragging air from a loose clamp. They all got an extra half turn and off we went again with the problem apparently solved. (The quickest way to check for this is with a piece of clear plastic hose that you put in the fuel line and look for bubbles in the fuel in the clear pipe section. If you have bubbles, then the loose clamp is upstream)!
Needless to say despite my apparent miracle cure, half an hour later, the same performance. Wife not impressed and loosing faith in the infallibility of husband etc.
I had recently transferred fuel from the reserve tank to the main tank, plus I needed some more fuel, so just in case it was a fuel fouling problem, (not sure how, but hope springs eternal!) we pulled in and went to fill up both tanks. The reserve tank filled fine, but when we came to filling the main tank, I only got about 30 litres in we fore a mass of pink foam came out of the overflow! Stopped filling and back to the drawing board.
Looking at the foam, it was obvious that the fuel was being foamed within the system, but the question was where and how?
Once again, my thoughts turned to leaking hoses coming from the main fuel tank to the lift pun and into the injector system, so up with all the bedding and check these hose clamps under the master cabin bed - all tight.
At this point I did not want to take anything else apart until I got home and as the motor would run if required on low revs, so I left it all alone and we sailed home, motoring the last bit into the marina on reduced revs, with wires face expressing some concern.
The following day, having been on the net and looked up everything it could, or could not be, plus checked the manuals that are stored under the seats on the boat, I decided to check the fuel pick up in the main tank.
It is not obvious in all the books, but the pick up is a plastic dip tube that sticks down to the bottom of the tank, which is covered by a fine wire mesh screen at the bottom; - you can't find it on the drawings, but it is there!
So, back up with the bedding, a major struggle to get the fuel feed hose off the tank top fitting that holds the dip tube, (cut hose off flush with end of fitting in the end and then cleaned it up and reinstalled with new cut end!) and then turn fitting lose and try to get out dip tube. Again, not an easy removal , but a certain amount of BFI (Brute Force and Ignorance) and out it came, with the wire mesh screen attached.
Needless to say this wire mesh screen was covered in some form of sticky goop that was completely restricting the flow through the mesh; hence the hunting at higher revs and foaming of the fuel in the injector and lift pump that was evident when we went to fill the main tank.
Removed dip tube, washed out the mesh filter end in a parts washer (do not remove it as it appears to be simply stuck on!) and blew it out, put it all back together, including changing the main fuel/water filter and also the small block filter, put excess amount of fuel conditioner into both tanks, bolted everything down and off we went! End of problem.
So if you engine starts bogging and you can't figure out why try the dip tube filter!
So I then went around the engine looking for loose hose clamps thinking that perhaps I was dragging air from a loose clamp. They all got an extra half turn and off we went again with the problem apparently solved. (The quickest way to check for this is with a piece of clear plastic hose that you put in the fuel line and look for bubbles in the fuel in the clear pipe section. If you have bubbles, then the loose clamp is upstream)!
Needless to say despite my apparent miracle cure, half an hour later, the same performance. Wife not impressed and loosing faith in the infallibility of husband etc.
I had recently transferred fuel from the reserve tank to the main tank, plus I needed some more fuel, so just in case it was a fuel fouling problem, (not sure how, but hope springs eternal!) we pulled in and went to fill up both tanks. The reserve tank filled fine, but when we came to filling the main tank, I only got about 30 litres in we fore a mass of pink foam came out of the overflow! Stopped filling and back to the drawing board.
Looking at the foam, it was obvious that the fuel was being foamed within the system, but the question was where and how?
Once again, my thoughts turned to leaking hoses coming from the main fuel tank to the lift pun and into the injector system, so up with all the bedding and check these hose clamps under the master cabin bed - all tight.
At this point I did not want to take anything else apart until I got home and as the motor would run if required on low revs, so I left it all alone and we sailed home, motoring the last bit into the marina on reduced revs, with wires face expressing some concern.
The following day, having been on the net and looked up everything it could, or could not be, plus checked the manuals that are stored under the seats on the boat, I decided to check the fuel pick up in the main tank.
It is not obvious in all the books, but the pick up is a plastic dip tube that sticks down to the bottom of the tank, which is covered by a fine wire mesh screen at the bottom; - you can't find it on the drawings, but it is there!
So, back up with the bedding, a major struggle to get the fuel feed hose off the tank top fitting that holds the dip tube, (cut hose off flush with end of fitting in the end and then cleaned it up and reinstalled with new cut end!) and then turn fitting lose and try to get out dip tube. Again, not an easy removal , but a certain amount of BFI (Brute Force and Ignorance) and out it came, with the wire mesh screen attached.
Needless to say this wire mesh screen was covered in some form of sticky goop that was completely restricting the flow through the mesh; hence the hunting at higher revs and foaming of the fuel in the injector and lift pump that was evident when we went to fill the main tank.
Removed dip tube, washed out the mesh filter end in a parts washer (do not remove it as it appears to be simply stuck on!) and blew it out, put it all back together, including changing the main fuel/water filter and also the small block filter, put excess amount of fuel conditioner into both tanks, bolted everything down and off we went! End of problem.
So if you engine starts bogging and you can't figure out why try the dip tube filter!
