1986 Johnson 115 VRO conversion questions..

[tallcar]

I have a failed VRO pump, yeah I know so do alot of people. I am pretty good with the wrenches since I currently own 42 outboards ranging from 1914 Evinrude to a 1960 Merc 400.

I am going to convert my VRO to a fuel pump and run 50:1 mix gas in it, but when it comes to the fuel pump I have some questions so here goes what info I have.


Fuel Pump Parts for 1982 Evinrude 115 hp E115TXCNB Outboard Motor uses per iboats Sierra part number 18-7352. My engine is a 1986 115 Johnson.


My Sierra catalog shows that same pump for use with 25-55 hp motors, but I have a 115 Johnson, actually 110 but who is really counting. Is this pump going to be sufficient for proper amount of fuel?

Looking at other sites, Marine engine shows this same pump for 140 hp engines in the early 80's era.. So again, will this pump be sufficient?

And on the wiring, which colored wires need what done to them so when I start this puppy up I won't get any buzzers?

Thanks billions

Richard

 

[ezeke]

Re: 1986 Johnson 115 VRO conversion questions..

It's risky. The 115HP of 1982 becomes the 90HP of 1986 because of a change in the rating system. A true 110 ought to use a pump that is rated for it or two of the lesser ones.

If you use too light a pump the engine can run lean at higher RPM and burn a piston.

The 2001 105HP uses a two pump system on the J105WRLSIF model. You can check that out here: http://evinrude.cust.shopatron.com/

 

[tallcar]

Re: 1986 Johnson 115 VRO conversion questions..

As I thought, now the issue becomes after 1986 it seems all of the larger motors used the VRO system, so maybe two of the smaller pumps or how about an electric fuel pump from a car, it is 12 volts and can easily handle the volume. not sure about it operating with too high of pressure.... thoughts?

Richard

 

[tallcar]

Re: 1986 Johnson 115 VRO conversion questions..

It's risky. The 115HP of 1982 becomes the 90HP of 1986 because of a change in the rating system. A true 110 ought to use a pump that is rated for it or two of the lesser ones.

If you use too light a pump the engine can run lean at higher RPM and burn a piston.

The 2001 105HP uses a two pump system on the J105WRLSIF model. You can check that out here: http://evinrude.cust.shopatron.com/

Umm those two pumps are over $200, two of the 18-7352 pumps each claim to supply up to a 55 hp at $44 per here on iboats, the $200 dual pump setup does not seem logical. I am in no way doggin ya, just crunchin numbers...

will the cheaper dual pumps do the job? each pump can supply one carb....

Again, thanks billions

Richard

 

[ezeke]

Re: 1986 Johnson 115 VRO conversion questions..

Have a good crunch. Wait 'til you see what replacing a piston costs.

You could use two of the Sierra pumps in the same manner as BRP did but if they could have done it reliably with one pump I am sure that they would have.

You use the same setup, the pumps combined outflow is in series to the fuel manifold.

 

[tallcar]

Re: 1986 Johnson 115 VRO conversion questions..

Have a good crunch. Wait 'til you see what replacing a piston costs.

You could use two of the Sierra pumps in the same manner as BRP did but if they could have done it reliably with one pump I am sure that they would have.

You use the same setup, the pumps combined outflow is in series to the fuel manifold.

I have removed the carbs, to ensure I have the shift linkage connected properly, just plain could not see in there.

I noticed that each carb was being fed by a different line (a tee in the line from VRO), so I am thinking that a fuel pump that supplies fuel for an engine up to 55 hp supplying each carb should do it. Now getting enough pulse from the engine is my next question. The current VRO, does it use a pulse from the engine, or some other means? If it does pull from the engine can I split that pulse or do I need to get from 2 different sources? I know alot of questions but it is my mother-in-laws boat, and I do not want it going kaboom on her.

You say that the pumps combined outflow is in series to the fuel manifold..

Coming out of the VRO the lines go to each carb, or am I misunderstanding? And I take it you believe this will work?

Again, thanks bunches

 

[Kpaul5257]

Re: 1986 Johnson 115 VRO conversion questions..

And on the wiring, which colored wires need what done to them so when I start this puppy up I won't get any buzzers?

This is the easy part as I had to deal with it today and received some help from this board. The VRO has 3 or 4 wires that plug into a connector. Just disconnect them at the connector & pull the VRO out. The connector that is left just needs to be taped off for corrosion or water.
I assume you have an oil tank on board. There is two wires coming off the tank and into the engine compartment. You can just cut these two wires and tape the ends off. That's it! No Alarm, but it will still work if you overheat the engine.

 

[pcrussell50]

Re: 1986 Johnson 115 VRO conversion questions..

or how about an electric fuel pump from a car, it is 12 volts and can easily handle the volume. not sure about it operating with too high of pressure.... thoughts?

Richard

I have not tried it myself, but some of the guys on the big forum about performance outboarding use automotive fuel pumps. just be sure to use a low pressure pump intended for carbureted motors, IOW 6-10psi or so. EFI pumps run 40psi or so, and modern HPDI pumps run something like 2000psi, if memory serves. You won't accidentally buy one of those, though as they'll cost you a grand or more.

if you use an automotive carburetor fuel pump, you will need to either wire it to your ignition switch "on", or give it it's own switch, preferably with a safety guard, guarded-on, so it doesn't turn off accidentally when bumped.

-peter

 

[kenmyfam]

Re: 1986 Johnson 115 VRO conversion questions..

Using a pump from a 1982 150hp on my 140HP looper for the last few years. No issues so far.
Here's a link to it.

http://forums.iboats.com/showthread.php?t=265363&highlight=Pre-mixer

 

[ezeke]

Re: 1986 Johnson 115 VRO conversion questions..

The least expensive alternative and the simple one is to convert a VRO to premix which costs nothing. Second is to convert the VRO to premix and upgrade the gasoline side of the pump with the repair kit which costs around $100.

Third cheapest but risky is to use a single conventional pump with the oversized nipples.

Best option outside the VRO but pricey is the VRO look alike that runs only premix.

Best option after that is two pumps in series as BRP uses on the 105HP motors. Click the thumbnail for a marked up diagram.

No conventional fuel pump is as powerful as the VRO/OMS pumps, period. Put a pressure gauge on them and see for yourself.

 

[tallcar]

Re: 1986 Johnson 115 VRO conversion questions..

The least expensive alternative and the simple one is to convert a VRO to premix which costs nothing. QUOTE]


Can you elaborate?

This seems most logical of all solutions.

Thanks

Richard

 

[ezeke]

Re: 1986 Johnson 115 VRO conversion questions..

You will need to mix TC-W3 with your gasoline at a ratio of 50:1.

Then run the engine to get the mix to the pump.

Then, cut and block the oil hose near the oil inlet nipple on the pump. You will need to force something into the oil hose and clamp it to make it airtight. The pumps originally came with a yellow fitting for this purpose.

After that you will need to disconnect and tape off the alarm wiring from the tank AND, disconnect and tape off the alarm wiring harness from the fuel pump.

That's all that is required.

If the pump malfunctions later, there is a repair kit to fix the gasoline side of the pump so that it can continue to be used as a premix pump for as long as the kits are available.

 

[tallcar]

Re: 1986 Johnson 115 VRO conversion questions..

so If I understand I will be using the oil pump to pump fuel? WOW simple and cost effective, thanks

Richard

 

[kenmyfam]

Re: 1986 Johnson 115 VRO conversion questions..

so If I understand I will be using the oil pump to pump fuel? WOW simple and cost effective, thanks

Richard

You would be using the fuel side of the VRO pump only to run premixed fuel.

 

[ezeke]

Re: 1986 Johnson 115 VRO conversion questions..

You will be blocking off the oil side of the pump and pumping premix through the gasoline side. There's a diagram here: http://continuouswave.com/whaler/reference/VRO.html

More on the conversion here: http://www.nitroowners.com/projects/VRO_the_removal.htm

(I don't know why it would take two hours as in the article. I rebuilt the pump and did the conversion in less time than that.)