2001 Johnson 90 VRO conversion

will941s

Chief Petty Officer
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Oct 1, 2007
Messages
540
2001 Johnson 90hp 2-stroke, VRO/60 Degree V-4 (the one with the plastic carb bodies)

About 3 months ago my VRO quit on the water and nearly destoryed the motor, I disconnected the VRO and plugged the line. Ran great ever since. Now it seems the fuel pump is going bad. Wont run unless your pumping the ball, and all lines are tight and in like new shape....filters are clean..etc.

I want to remove the whole assembly....VRO/Fuel pump, vapor separator...everything. All I want to keep is te primer. I was reading some threads on here about how you can install a regular pulse pump and that will replace the old system, all the lines and everything will still work.

Question is: This motor doesnt use a pulse through the block, it uses a line out of the intake manifold, so I guess I can mount the new pump on a bracket. Does anyone know the part number the Johnson/Evinrude pump that has the external pulse nipple?

Is there anything else extra I will need, besides a "t" fitting to feed both carb banks off one outlet?

Should I expect to have to tune anything to accomodate for less fuel pressure, or will the pressure change at all?

Figured I can do all this for still a fraction of the price of just the VRO fuel pump, and have a MUCH better system and easier to maintain, after all....im not using the VRO oil pump anyway

Thanks in advance!!!!
 

will941s

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Oct 1, 2007
Messages
540
Re: 2001 Johnson 90 VRO conversion

Thanks a million!! Is there anything else I need to change/install for this system to work?
 

Daviet

Fleet Admiral
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Sep 24, 2008
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8,958
Re: 2001 Johnson 90 VRO conversion

You will need to make a mounting bracket of some sort, fuel line to plumb it and you should be good to go.
 

woody66912

Senior Chief Petty Officer
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Jul 12, 2008
Messages
690
Re: 2001 Johnson 90 VRO conversion

Daviet I don't think that will work his VRO feeds into the vst, if he got a hold of the out put nipple from a
vro 2 than he could rig something up.
 

will941s

Chief Petty Officer
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Oct 1, 2007
Messages
540
Re: 2001 Johnson 90 VRO conversion

From the tank, I have a line that feeds into the in-line filter, then out the filter into the VRO pump. Out the pump into a Vapor Serparator box, then out the box and t's into the carb banks. Prime is still controlled by a idle primer. The VRO pump is fueled by a pulse line out the front of the intake cover controlled by a pulse limiter. Other than the VRO pump that primes the entire system, there is no electric fuel pump....just the pulse activated VRO pump.

This is what my theory of using a regular pulse activated pump to fuel the carbs was based off of. Does this motor have a VST like a 4-stroke?

The "vapor" box looks very small, and plastic. Seems like it wouldnt be able to handle alot of pressure like a VST, and why would you need a VST to control other than being plastic.....regular carbs?

Not doubting anyone, just asking......which is why I put the question on here, I knew I would get great advice!!!

Surly im not the only one who is attempting this....seems like to correctly remove the VRO would be to eliminate the entire system
 

woody66912

Senior Chief Petty Officer
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Jul 12, 2008
Messages
690
Re: 2001 Johnson 90 VRO conversion

OK removing the whole system is the only way, good thinking. Never seen this done or tried it. Let us know how it turns out.

This is what my theory of using a regular pulse activated pump to fuel the carbs was based off of. Does this motor have a VST like a 4-stroke? ---- NO.

There will be A whole lot of re -plumbing.

Let us know how it turns out.
 

will941s

Chief Petty Officer
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Oct 1, 2007
Messages
540
Re: 2001 Johnson 90 VRO conversion

Planning on taking pics through the process and posting them on here, if this works, then it should help alot of people. It actually seems a whole lot more simple than it looks.

Should I remove the pulse limiter that pulses the pump and just use a regular open nipple, or leave it in there?
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: 2001 Johnson 90 VRO conversion

If you remove the VST and the little vaper pump, you may not have lubricating to the upper main bearing. Take the nipple connecting the
VRO pump out of the pump, connect a fuel line to the nipple reinstall nipple in VST. Yoy may have to make a bracket to hold the nipple in place. The pressure inside the VST is the same as in the carbs float bowls.
 

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: 2001 Johnson 90 VRO conversion

How does the VST feed the upper bearing? The only lines connecting the entire bracket to the engine is the two fuel lines to the carbs, the pulse line and the non functioning oil line. Which lines feed oil to the upper main? Is it the two vac lines coming off the top of the vapor box? Those appear be receiving, not sending anything to the motor. Each of the 4 carbs does have a float bowl.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: 2001 Johnson 90 VRO conversion

The 2 small hoses that are T into the vapor pump, also lubricate the upper mail bearing. If you remove the pump and T, the remaining hose between the 2 cylinders should be check to insure the pulse flow is toward the upper main bearing.
 
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