Model:
====
Supplies:
=====
+ wrenches, sockets, pliers, etc
Hi everybody,
I've got so much information and help from this forum that I wanted to repay you by sharing my experience converting my VRO pump to a conventional fuel pump.
Little advice, read the entire article before you decide to do the switch. It's good idea to understand the whole process first so you know what you're getting yourself into. Your engine manual can also be useful in addition to these instructions. I also want to stress that I am not an outboard mechanics, so I can't guarantee anything... Just sharing my own experience.
Little background first. For the past few weeks, I was starting to have intermittent problems reaching normal WOT speed. It would run fine for hours then sit for a while, then start acting up. My RPM would go up and down and up and down, etc to finally got stuck down at 2000 RPM. Checked the S.L.O.W. first, but seemed to be working fine. then removed and inspected the tank fuel hose and the primer bulb. No issue here either. Tries to squeeze the bulb at WOT, and it did start to speed up again for a little bit then down again. I had just rebuilt the carbs so I knew the issue was definitely not there. Compression fine, ignition fine... I removed the VRO pump, checked all fuel lines between pump and carbs, and checked out pulse limiter for restriction as well. I finally concluded that my VRO pump was guilty.
I've been pre-mixing since day 1 so considering the price of a new VRO, I decided to go with a conventional fuel pump. Went to the BRP website, checked out the latest available fuel pump for 3 cylinders 70HP, and came up with part number 438557 (replaces original part number). Went to my local dealer, bought the pump and 2 feet of 5/16 fuel hose.
This is how I proceeded... Try to memorize the position of the hoses as you disconnect them.
While you're at it, check the the recirculation fuel hose is tightly clamp to the crankcase.
Now you can start working on installing the new fuel pump. There is a little seal between the engine cover fuel fitting and the fuel hose going to the pump. Mine got damaged when removing the fuel hose from the inside. You can get a replacement for a couple of box.
It's good idea to grease the fittings with a little bit of motor oil before you insert them into the hose. It'll make the job easier and prevent damaging the fittings and hoses.
At that point the system should be operational. Plug back your fuel tank hose to the engine cover fitting, unscrew the pump cover a little bit and squeeze the primer bulb. After a little bit, you should see fuel coming out of the fuel pump cover. Re-tighten the fuel pump cover, GENTLY. Do not over tighten or you will damage the pump cover.
Put the electric starter back on and crank the engine on (Don't forget the water... Test tank or hears). The engine should start easily. Let run at idle for a few minutes to make sure it's pumping fuel properly.
Now you need to secure the fuel pump to the engine block As far as I know, there is no OEM bracket to do so, so you'll have to make it yourself. I used a sheet of anodized aluminum to cut be a custom L-style bracket from a cardboard template. To make sure the pump is firmly hold into place, make sure you use both holes at the bottom of the pump, otherwise it will rotate with the engine vibrations.
You can now put the intake manifold and appropriate gaskets back on. As usual, it is not recommended to re-use the old gaskets. Make sure you use a proper gasket sealant to avoid fuel and air leaks. Don't forget the recirculation fuel hose at the back of the intake manifold.
That's pretty much it, now you just have to test it on the water at WOT. Make sure all your connections are tight before you leave, and check for fuel at the bottom of the engine lower cover to make sure there is no leak in the line. I strongly recommend you testing this for the first time in a controlled environment, either a canal or a lake, upwind so you can drift back in case of engine failure. Oars are a must !
Hoped that'll help. Enjoy !
==! Pictures to come soon !==
====
- Evinrude 1992 70HP
Supplies:
=====
- 2ft of 5/16 OMC fuel hose
- conventional fuel pump (depending on model)
- 6 hose clamps (stainless steel or ratchet style)
- Intake manifold and cover gaskets
+ wrenches, sockets, pliers, etc
Hi everybody,
I've got so much information and help from this forum that I wanted to repay you by sharing my experience converting my VRO pump to a conventional fuel pump.
Little advice, read the entire article before you decide to do the switch. It's good idea to understand the whole process first so you know what you're getting yourself into. Your engine manual can also be useful in addition to these instructions. I also want to stress that I am not an outboard mechanics, so I can't guarantee anything... Just sharing my own experience.
Little background first. For the past few weeks, I was starting to have intermittent problems reaching normal WOT speed. It would run fine for hours then sit for a while, then start acting up. My RPM would go up and down and up and down, etc to finally got stuck down at 2000 RPM. Checked the S.L.O.W. first, but seemed to be working fine. then removed and inspected the tank fuel hose and the primer bulb. No issue here either. Tries to squeeze the bulb at WOT, and it did start to speed up again for a little bit then down again. I had just rebuilt the carbs so I knew the issue was definitely not there. Compression fine, ignition fine... I removed the VRO pump, checked all fuel lines between pump and carbs, and checked out pulse limiter for restriction as well. I finally concluded that my VRO pump was guilty.
I've been pre-mixing since day 1 so considering the price of a new VRO, I decided to go with a conventional fuel pump. Went to the BRP website, checked out the latest available fuel pump for 3 cylinders 70HP, and came up with part number 438557 (replaces original part number). Went to my local dealer, bought the pump and 2 feet of 5/16 fuel hose.
This is how I proceeded... Try to memorize the position of the hoses as you disconnect them.
- Removed the air silencer cover, gaskets, and manifold. Also removed the recirculation fuel hose going to the crankcase from the back of the manifold.
- Removed the electric starter (3 bolts) on the port side.
- Removed the two bolts holding the VRO pump against the crankcase (intake manifold side).
- Disconnected every hoses from the VRO pump.
- Disposed of every hoses between pump and other elements. You can always keep those if you want to but since you're already in, might as well replace everything. Hoses are cheap. Also, if you keep the old ones, you may have trouble positioning the new fuel pump because of the shape of the original hoses.
- Removed the clamp holding the inline fuel filter from the exhaust manifold.
While you're at it, check the the recirculation fuel hose is tightly clamp to the crankcase.
Now you can start working on installing the new fuel pump. There is a little seal between the engine cover fuel fitting and the fuel hose going to the pump. Mine got damaged when removing the fuel hose from the inside. You can get a replacement for a couple of box.
It's good idea to grease the fittings with a little bit of motor oil before you insert them into the hose. It'll make the job easier and prevent damaging the fittings and hoses.
- I positioned the new pump where the hold VRO was, parallel to the exhaust manifold. The front of the pump is aligned with the front of the exhaust cover. The height is not really important, but position it height enough to avoid bending the fuel host too much. Note that you can unscrew the pump cover to rotate the fuel intake fitting.
- Cut a length of 5/16 fuel hose just long enough to go from the engine cover fuel fitting to the new pump fuel intake fitting (the plastic one in the front). I had mine go from the fitting to the front of the exhaust cover then up and back to the pump s I don't have too sharp of a bend. Clamp the hose tightly using ratchet type plastic clamps or stainless steel hose clamps. Ty straps are not recommended here.
- Cut a length of 5/16 hose to go from the very back fitting on the fuel pump to the pulse limiter on the port side of the engine crankcase. If you cut too long, you're going to have a hard time positioning the pump at the desired hight, so dry fit before you do your final cut. Clamp tight.
- Cut a length of 5/16 hose to go from the pump middle fitting to the carburetors distribution tee. Clamps tight but be careful with the Tee fitting as it's plastic and will be crushed if too tight.
At that point the system should be operational. Plug back your fuel tank hose to the engine cover fitting, unscrew the pump cover a little bit and squeeze the primer bulb. After a little bit, you should see fuel coming out of the fuel pump cover. Re-tighten the fuel pump cover, GENTLY. Do not over tighten or you will damage the pump cover.
Put the electric starter back on and crank the engine on (Don't forget the water... Test tank or hears). The engine should start easily. Let run at idle for a few minutes to make sure it's pumping fuel properly.
Now you need to secure the fuel pump to the engine block As far as I know, there is no OEM bracket to do so, so you'll have to make it yourself. I used a sheet of anodized aluminum to cut be a custom L-style bracket from a cardboard template. To make sure the pump is firmly hold into place, make sure you use both holes at the bottom of the pump, otherwise it will rotate with the engine vibrations.
You can now put the intake manifold and appropriate gaskets back on. As usual, it is not recommended to re-use the old gaskets. Make sure you use a proper gasket sealant to avoid fuel and air leaks. Don't forget the recirculation fuel hose at the back of the intake manifold.
That's pretty much it, now you just have to test it on the water at WOT. Make sure all your connections are tight before you leave, and check for fuel at the bottom of the engine lower cover to make sure there is no leak in the line. I strongly recommend you testing this for the first time in a controlled environment, either a canal or a lake, upwind so you can drift back in case of engine failure. Oars are a must !
Hoped that'll help. Enjoy !
==! Pictures to come soon !==