Fuel pump issues, VRO not working? converting it to a regular pump

[mclothier3]

I am in the middle of getting a 1995 Johnson 50 running after sitting for the last 4 or 5 years. Ive replaced the water pump, kitted the carbs, replaced fuels and oil lines, etc.

The motor does run, but Im having issues. It fires right up and seems to idle fine, but out on the water... anything over 2000 rpm and it dies out, like its starving for fuel. I can push and hold the ignition switch and that helps keep it running. I can run it in the driveway on the muff and it does the same thing, idles fine... bump up the rpm to 3000 and it runs ok for 10 seconds, then speeds up and dies out. I even made sure the fuel was getting to the pump by pumping the bulb to keep the fuel filter full.

Im assuming the original VRO pump isnt working like it should. I checked the pulse limiter and it looked very clean. I know there are certain checks that can be made to determine if the VRO pump is working or not, but at this point I think Im done with it. I dont want to spend any more money on it not knowing if it will work or not. and if it isnt... Im not spending $400 or more to replace it.

So I ordered a regular non VRO pump and it should be here sometime next week. I have looked at the VRO conversion thread and still have questions.

Ok so I remove the wiring to the VRO pump and the two wires going to the oil tank... by doing that, will it disable the warning horn for overtemp? Im assuming that removing it will just disable the VRO warning beeps.

Anybody have a better explanation or picture on how the fuel lines should be? Assuming from the fuel inlet fitting, I should have a line going direct to the inlet side of the pump, then another from the outlet side of the pump to the inlet of each carb, what about the fuel primer system? Should I also use the separate fuel filter or just rely on the filter screen in the new pump?

Thanks for the help!

 

[pn]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

"I even made sure the fuel was getting to the pump by pumping the bulb to keep the fuel filter full."

now what this says to me is that fuel is getting to your float bowls and still your motor dies, very odd. The motor should run just fine by pumping the primer bulb. I've changed out my vro to little pumps, just route the lines like the original pump set up. Is your spark good and strong i'm suspecting coil or ignition stuff?
I'd trust a separate filter over the one in the pump but i don't think that little mesh is much restriction.

 

[boobie]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

Taking the wires off that go to the vro oil tank won't affect the temp sender.

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

Correct me if Im wrong but I believe that pumping the bulb like I did just makes sure the fuel is getting to the pump.... and if the pump isnt working then it will die because its not supplying the carbs with fuel.

I think I proved this by letting it rev up a bit and when it starts to die I push the ignition switch which puts fuel into the carbs by way of the electric primer system.

I am 100% convinced this is solely a fuel supply issue, Spark has always been good. I just think that since it sat for so long that something is wrong with the VRO pump, and I really cant justify the $400 (online) plus to replace it. Local marina said $700 cash and carry.

I dont mind doing the pre-mix. So converting over to a regular pump is ok with me.

thanks for the help.

 

[pn]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

Ok if you don't believe me than try this for yourself. Remove the float bowl drain screw and pump the primer bulb... Fuel should go right through your pump and into the carb float bowl spilling out the drain screw. If it doesn't somethings wrong, bulb, hoses, needle, float, lines clogged, no fuel etc.

look for the small fuel pump with three barbs they are all the same 15-200hp about 50 bucks. Bury the VRO next to the tomato plants.

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

Its not that I dont believe you, but the way it acts... it has to be a fuel issue. And I wasnt sure that pumping the bulb also pumped fuel directly to the float bowl. I was just looking at the fuel level in the filter and kept pumping the bulb to keep it as full as I could.

I went ahead and stripped all the VRO stuff off of it yesterday, and I have the regular small pump on order (should be here later this week)

When I removed the pulse limiter It still looks nice and clean, but I was thinking that it was supposed to act like a check valve? But I could blow thru it in either direction with no restriction. Not like it matters now... but just trying to understand it.

I did go thru the carbs and put kits in them, it is very possible I have the floats set wrong since I basically eyeballed it so that the needle would close when the top edge of the float was parallel with the bottom edge of the carb body. maybe not letting in enough fuel?? At any rate I will also doublecheck this while I have it all taken apart.

Thanks again for the help, I do appreciate it. not sure the tomato plants will like it though? lol

 

[pn]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

So you didn't do the test and are stuck. Dianosing problems one and fixing them step a time is how things get done, im sorry good luck.

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

I bought the service manual, some of the tests require equipment I dont have, so I dont feel like buying stuff I will only use one time and / or paying $75 an hour to have it diagnosed for something I was thinking of changing out anyways.

Besides... if the VRO pump is bad, I wont be buying another one because of the cost. The problem could be something as simple as the pulse limiter since I read in the service manual that it is supposed to act like a check valve, but saw no specific test for it.

All of that is pretty much a moot point anyways, I was just trying to understand how it worked.

Ive got a regular pump coming, and my original question on this thread was about the overtemp warning, and the fuel lines, which I think I have been answered.

No need to be sorry, Ill figure it out.

I will update with results after I get the new pump installed.

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

The new pump arrived today, got it all installed.... and I believe its all better. I ran it in the driveway on the muffs and ran it up to 3000 rpm and it stayed running, not once did it go lean and speed up and die.

I do need to adjust the floats because now it appears that the bottom carb is leaking fuel... never did that before.

A little fine tuning and Ill try it on the water.

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

sorry for the late update, but I did get it on the water, and after fine tuning the float position, it runs like a champ. :joyous:

 

[takeemmac]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

what did you do with your wires that went to the vro pump....do you not have a tach

 

[mclothier3]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

I just unplugged the VRO pump and tucked the connector back into the harness. Yes it has a tach and it works fine.

All in all it was a very simple deal to remove, Unplug the pump and remove, remove the pulse limiter and plug the crankcase, remove the oil reservoir tank + hose and wires, cap the oil inlet where it goes into the motor, install the new fuel pump and re-plumb to both carbs and fuel primer.

 

[bakerjw]

Re: Fuel pump issues, VRO not working? converting it to a regular pump

I just rebuilt the carbs on my 1990 XP150 and have been experiencing the same symptoms that you were seeing. The motor runs fine when cold but later in the day has trouble getting above 3000 RPMs. It bogs down unless I push in the key to give it a shot of gas. I suspect that I need to readjust the floats in the carbs; however, I still suspect a poor fuel pump. The VRO has been removed.