narmstrong26
Cadet
- Joined
- Aug 14, 2009
- Messages
- 7
Let me start off by saying I am not a mechanic marine or otherwise. A lot of people will say putting a 12V pump on a boat motor is a bad idea. I think it is perfectly safe if done properly. Use my how to here as you like but I didn't publish this to start a debate.
My story is this last year I bought a Four Winn's Fling with a blown OMC Turbo Jet engine. I didn't know a thing about the engine other then the fact that it had to be rebuilt. I rebuilt it myself and got back on the water. I had one constant problem though. The engine started extremely hard and often stalled at idle or low speed. This made using my boat less then enjoyable at times. I checked and replaced all the vacuum lines on the engine. I even took the VRO pump out and check it over per the book's spec. I also replaced the vacuum pulse limiter or whatever its called. All this and my engine still died at low speed. The VRO passed all test but I knew I was not getting enough fuel. A vacuum test on the engine confirmed good vac so I was left to believe that even though my VRO tested good it was getting tired and would have to be replaced. Since I had already gone to premixing and bypassed the oil injection portion of my VRO it didn't make a lot of sense to keep it around in my book. I also didn't care for the option of replacing the VRO with a look alike that only pumped fuel and still ran on vacuum. I searched forum after forum and found little information on changing the pump over to 12v. With some research on my own I decided that a low pressure 5-7 psi 12v fuel pump would be a good replacement for the VRO. I did not actually remove my VRO pump instead I fed fuel through it by installing the 12v pump between the VRO and the fuel tank. This is how I did it:
You will need the following:
Mr. Gasket model 12v fuel pump
One 14-16 gauge eyelet
Two 3/8 hose barbs
Flat head screw driver
Phillips head screw driver
Terminal crimper's
7/16 Wrench
First prep your new pump by installing the 3/8 hose barb's (the pump comes with 5/16 barbs but the line in the boat is 3/8) and installing the eyelet on the red power wire. (the black wire should already have an eyelet installed)
Next you will need to remove the factory primer pump (may not be on all models) I would encourage you to leave any primer bulb or install one just incase. YOU DO NOT NEED TO REMOVE THE VRO PUMP.
Next you need to mount the new pump, use one of the bolts and holes from the old primer pump. Connect the fuel lines and clamp them down tight as well.
Making sure that the key or ignition switch is in the off position and that the main fuse is pulled or negative battery cable is disconnected, connect the red wire of the fuel pump to the purple wire on the engine terminal strip. Connect the black wire to a ground (I used the bolt on top of the VRO pump housing.
Last step reconnect the power cable to the battery or reinstall the main fuse. Cycle the key to on or turn on your ignition switch. Listen for the fuel pump if you can hear it humming softly you did things right. Observe the fuel lines to make sure you have no leaks.
Head out to the lake and enjoy your boat again. If yours went as well as mine you spent around 35 dollars and took about 20 minutes of your time.
My story is this last year I bought a Four Winn's Fling with a blown OMC Turbo Jet engine. I didn't know a thing about the engine other then the fact that it had to be rebuilt. I rebuilt it myself and got back on the water. I had one constant problem though. The engine started extremely hard and often stalled at idle or low speed. This made using my boat less then enjoyable at times. I checked and replaced all the vacuum lines on the engine. I even took the VRO pump out and check it over per the book's spec. I also replaced the vacuum pulse limiter or whatever its called. All this and my engine still died at low speed. The VRO passed all test but I knew I was not getting enough fuel. A vacuum test on the engine confirmed good vac so I was left to believe that even though my VRO tested good it was getting tired and would have to be replaced. Since I had already gone to premixing and bypassed the oil injection portion of my VRO it didn't make a lot of sense to keep it around in my book. I also didn't care for the option of replacing the VRO with a look alike that only pumped fuel and still ran on vacuum. I searched forum after forum and found little information on changing the pump over to 12v. With some research on my own I decided that a low pressure 5-7 psi 12v fuel pump would be a good replacement for the VRO. I did not actually remove my VRO pump instead I fed fuel through it by installing the 12v pump between the VRO and the fuel tank. This is how I did it:
You will need the following:
Mr. Gasket model 12v fuel pump
One 14-16 gauge eyelet
Two 3/8 hose barbs
Flat head screw driver
Phillips head screw driver
Terminal crimper's
7/16 Wrench
First prep your new pump by installing the 3/8 hose barb's (the pump comes with 5/16 barbs but the line in the boat is 3/8) and installing the eyelet on the red power wire. (the black wire should already have an eyelet installed)
Next you will need to remove the factory primer pump (may not be on all models) I would encourage you to leave any primer bulb or install one just incase. YOU DO NOT NEED TO REMOVE THE VRO PUMP.
Next you need to mount the new pump, use one of the bolts and holes from the old primer pump. Connect the fuel lines and clamp them down tight as well.
Making sure that the key or ignition switch is in the off position and that the main fuse is pulled or negative battery cable is disconnected, connect the red wire of the fuel pump to the purple wire on the engine terminal strip. Connect the black wire to a ground (I used the bolt on top of the VRO pump housing.
Last step reconnect the power cable to the battery or reinstall the main fuse. Cycle the key to on or turn on your ignition switch. Listen for the fuel pump if you can hear it humming softly you did things right. Observe the fuel lines to make sure you have no leaks.
Head out to the lake and enjoy your boat again. If yours went as well as mine you spent around 35 dollars and took about 20 minutes of your time.