Replace a VRO pump with a standard fuel pump

Ok I am totaly new to this forum and totaly lost when it comes to finding a possible replacement to the VRO pump on my 2004 50 hp Jonhson. It's 2 stroke, I assume of course, carborated, and the model # appears to be 50plsoc. I'm not the least bit mechanicaly inclined, but I'm learning, and several of of my more mechanicaly inclined friends and I have come to the conculsion that it must be the fuel pump. In my case this wonderfull VRO that everyone raves about, and seems to run for the very low price off about $400. I have ruled out the fuel line from tank to outboard, replaced line and primer bulb, followed instructions posted on a threads here to disconect the oil side of the VRO, and am now mixing 50:1 in the gas tank. The engine will still not run wide open, or sometimes at lower RPMs, unless you pump the primer ball. Actually the engine works great when I become the fuel pump, but my hand gets tired and it's not allways easy to know where I'm going when I'm pumping the ball. So basicaly at this point, with the help of friends who know more, I want to switch out the VRO for a cheaper standard fuel pump. What standard pump can I use? Are there more than one? Is this some great secret being held on to by Johnson Evinrude mechanics. I've found countless sites online selling fuel pumps and I have many local marine stores in my area. Surely some of them must have a pump that would work for me. I dont need this to fix to be "by the book", I need to get on the water and get use out of the boat and engine. Can anyone help me get a part number? Has anyone made a similar switch or conversion?

Re: Replace a VRO pump with a standard fuel pump

the Maxrules.com website will tell you what pump to buy and even sell you one.

have you tried a portable tank to see if the problem still exists? Have you checked the pulse limiter? Have you checked the vapor seperator cover gasket? If not, it will be quite likely that the problem will still exist with the new pump.

Re: Replace a VRO pump with a standard fuel pump

Thanks for the reply. I guess now I'm left with more questions than answers. It's a portable tank that im useing. It appears to be in good condition, and I did replace the fuel line assembly. There are a dozen or so other fuel looking hoses inside the outboard, perhaps they have failed, or leak as well. I'm not really sure what the vapor seperator is or even where it is for that matter but I undersand if it's gasket is bad then so is the vacuum. I'm at loss to the purpose of a pulse limiter. I will try again to read up on it. Perhaps all of this is way out of my league. I was really hopeing that for it to be such a plain case of a gas starved engine that the easiest thing to do would be to replace the VRO with a standard pump. I was told the VROs often went bad. Perhaps what you are sugesting is an even easier and cheaper solution. Should I get an owners manual, can you think of an online source that might help educate me, or should I just bite the bullet and take it to a mechanic when I have the money? I'm thinking that regaurdless I should no more about an engine that is takeing me out into open water and back. Thanks again.

Re: Replace a VRO pump with a standard fuel pump

I've heard some early vro's (way before your 2004) had some issues and some folks disabled 'em and ran premix. That bad rep has had people disabling perfectly functional vro's for years. I'd try to fix the issue and still have the vro.. My .02

Good luck!

Re: Replace a VRO pump with a standard fuel pump

Thanks for replying kbait and Chris. I still have the oil reservoir and the VRO can be pluged back in. I dont think the alarm works so perhaps once again I should probably have a mechanic look it over. I was actualy glad to get the oil reservoir out of the back of the boat. It's a 13 ft Whaler, and I'm tight for space. I also havent had a boat with outboard since my teens. That outboard ran straight mixed gas. I guess I was hopeing to keep things simple and framiliar. I was hopeing to hop on the boat and enjoy it with out dumping alot more money into it. Part of haveing a boat is keeping it working, and I will be on the water soon enough. Thanks!!

Re: Replace a VRO pump with a standard fuel pump

Throwing parts at it might solve the problem, but if you are going to do your own maintainence and trouble shooting, get a factory service manual, otherwise you are flying blind.

Re: Replace a VRO pump with a standard fuel pump

A service manual will help troubleshoot the vapor seperator and pulse limiter. You may not have a pulse limiter, BTW.

You might look on the crowleymarine.com parts list and see if you can start to identify some of the components of the fuel system.

Re: Replace a VRO pump with a standard fuel pump

i just completed a conversion on my 2000 50 hp johnson 2 cycle. i removed the VRO, pulse limiter nipple which connects to the VRO via a hose, unlpugged the VRO wire haress in the lower pan area port side. plugged the pulse limiter tap with a napa brass pipe plug after opening threads slightly with a tapered pipe plug tap of the same thread size. had to do this because the closest sized plug I could find was slightly larger diameter but the tap worked ok, just fill the tap flutes with grease which will catch any metal shavings. maxrules.com was great, they directed me to a diaghram fuel pump that was half the price (about $65) of the pump I thought I needed. ask for the mount screw n he will include them no charge. it mounts on port side of motor just remove the plug that is in the pulse hole (pulse hole is what drives the pump) I took the starter off so I could re-hose the set up with new hose and in-line fuel filter. was able to use the old 5/32 inch fuel lines that come off the plastic fuel manifold, just connect the output side of the pump to it. a bit tight fitting the fuel lines in but take your time, cut the fuel lines an inch longer then you think you need and save the frustration of finding thaat you cut it 1/2 in too short . I also rebuilt the carbs. I just took it out on the Potomac River yesterday and it never ran so well. I am very happy with this simply setup and it is so much easier getting to the carbs with the VRO gone. I could pull both carbs now, clean them and have them reinstalled in an hour or 2. My marine mechanic looked at my work and said it was fine. In fact he has a johnson VRO setup on his boat and always runs 100:1 fuel in the tank because he knows if the VRO oil pump fails he could fry his motor. Good luck, go for it.

Re: Replace a VRO pump with a standard fuel pump

kbait said:

That bad rep has had people disabling perfectly functional vro's for years. I'd try to fix the issue and still have the vro...

Good luck!

Click to expand...

Got to agree with kbait on this one. I've done a ton of reading on VRO's, especially the VRO2's. The newer ones are very dependable, and if properly tested and maintained, will give years of trouble free service. All too often people are removing perfectly good VRO pumps, blaming them for failure, when in fact the whole problem started with a bad hose clamp or a cracked/borken/loose hose.

Re: Replace a VRO pump with a standard fuel pump

Thanks for all your replies. Angel I do beleive I'm going to try to do what you have done. Seems to me that while I'm taking off the VRO and putting a standard diaphragm pump on I can get a better look at the conecting hoses to the carbs. Wont I also have fewer hoses with a standard pump? I am worried that my hoses aren't clamped down and conected well. I am worried that the current fuel delivery system with all its hoses and components is just complicated for me. Small boat, small engine. I only paid 1500 for it, but now I'm broke. If I can do this with out a mechanic I will be getting some use out of the boat sooner. I'm still a litle confused to the pulse limiter's role in this. Acording to crowleymarine.com my model does have a pulse limiter. Will it still use a pulse limiter after the conversion? Was that the hose you caped? And "remove the plug that is in the pulse hole (pulse hole is what drives the pump)", will I find that on the new pump or the engine it self? Also should I order extra hose and a fuel filter, and I wonder if maxrules.com would mind terribly if I bothered them about all of this? I must be driving Y'all crazy with my entrant questions. Maybe one day it will be me giving back and giving my two cents. Thanks again!

Re: Replace a VRO pump with a standard fuel pump

Pump # 438559 will work. You will have alot of room to work when you remove the VRO pump and related hoses. You can still use the pulse limiter. Going to the new pump, you will have:

One fuel supply line from the fuel tank

One line from the pulse fitting

One fuel line to the carbs

Re: Replace a VRO pump with a standard fuel pump

This is before and after pics of the replacement pump on my 70 HP.

Re: Replace a VRO pump with a standard fuel pump

Wow thanks rickdb1boat, thats exactly what I need, and I'm pretty sure I could do it my self. I might have a buddy of mine help me. I'm assuming that the 'out' hose from the pump meets some type of tee or junction to then send two hoses off to the two carburators? There is an existing larger hose from the VRO that plugs into a plastic fitting (fuel manifold?), that then sends off three smaller hoses. I can see two hoses go to the carb, where does the other one go, is that what Angel was talking about capping. On top,and conected to both carburators is an even smaller hose, not conected to that junction. Is that the hose injecting the oil, and what comes of them after the conversion? I think I'm actualy begining to understand this enough. Thank for all your help!!

Re: Replace a VRO pump with a standard fuel pump

The larger hose you see branches of to 3 smaller lines. One to each carb and the other goes to the fuel primer solenoid. The original oil line coming from the oil tank connects to the VRO pump, where it internally mixes the oil in with the fuel.

Re: Replace a VRO pump with a standard fuel pump

I believe Angel installed a pump that bolts directly to the engine block (433387). In that case, you would remove the existing pulse limiter and install a plug in it's place. Then the new pump is mounted directly over another port in the block (After removing a different plug) where it gets it's pulse. Either way will work..

Re: Replace a VRO pump with a standard fuel pump

I found the fuel primer solenoid. It's tucked a way on the otherside and I cant see where the hoses come in at, but I guess it stays. So the tiny hoses on top of the carbs inject some type of primmer fuel? That makes more sence. The 'out' valve on the new fuel pump will conect to the large hose that branches to 3 smaller lines, the 'in' valve to the fuel tank, the left over one to the pulse limiter, thus completing the fuel conections from the VRO minus the oil stuff? Is it realy all starting to make. I think it's time to order a pump and perhaps more hose and clamps. Thanks so much. If Y'all are ever down here in Miami, I'll take you out on the boat to grab lobster.

Re: Replace a VRO pump with a standard fuel pump

this was my first attempt at this and happily it turned out ok. I don't know that your motor is the same as mine so verify that this will work for you. I only have a 17 gallon on-board tank so I don't mind premixing my 50:1. I just pulled my receipt for the fuel pump I put on my 2000 50 hp. Apparently there was more than 1 fuel pump that would have worked I think thats why you can use the pulse limiter that is used for the VRO to drive one of these basic diaghram type fuel pumps, but I did not go that route. Mastertech marine sold me pump part # 438556 for $64 (I believe the markings on it was "Sierra". this pump mounts on the port side of the crankcase about 3 inches aft of the electric starter motor where there is 3 threaded taps. the middle tap is plugged (just remove the plug). the other 2 holes are for the mount screws. it comes with a gasket which will seal the 3rd middle tap which is where the pulse of air comes from to operate the pump. I purchased the OMC in-line filter and some new hoses, cut carefully, and got it all routed nicely without a hitch. All this was probably unnecessary but I like to keep things simple and When my motor isn't running right I don't want to be constantly wondering if one of the many VRO hoses has sprung an air leak that I just have failed to find. I only get out at best once per month and I would prefer to spend my time fishing not chasing down air leaks. Just me. I hope this helps.

Re: Replace a VRO pump with a standard fuel pump

Wow Angel this sounds even easier. I can see right where the pump would mount on my engine. Two threaded holes and a screw inbetween the holes. I'm assumeing I unscrew that for the pulse hole. I'm pretty sure it will work, I will make sure with Mastertech marine . Does the 'out' line from the pump still conect up to that plastic fitting that sends off three smaller hoses? Will I need a plug for the hole from the existing pulse limiter or can I use the plug from the new hole? It sounds great though. I'll redo all the hoses, new filter and I should be be good to go. Thanks for all your help!!

Re: Replace a VRO pump with a standard fuel pump

Rick clarified my point accuratley> either way will work. my way eliminated the need to run the pulse limiter hose to the fuel pump(but that fuel pump must have a nipple to receive the hose). my pump does not have that nipple for the pulse hose because it gets the pulse directly from the pulse hole in the block where you mount the pump. there is a hole in the back of my pump the mounts directly over the pulse hole in the block

Re: Replace a VRO pump with a standard fuel pump

Thanks Angel, Its all making sence now. I'll let you all know how it turns out. Cant thank you all enuff!!