VRO conversion to Diaphragm-Displacement Pump

ANGEL-1

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Joined
Feb 5, 2010
Messages
12
2000 50 HP Johnson with VRO fuel/oil system, J50PLSSM In an effort to simplify the fuel system i plan to remove the VRO and install a diaphragm-displacement type pump and use pre-mixed 50:1 fuel. My 50 has the 2 mount taps with the pulse hole between them where the diaphragm pump mounts on the port side of motor. I thought I would simply remove the VRO & VRO pulse limiter and install a gasketed bolt/plug in the pulse limiter tap. so...I checked a parts breakdown for the 50 HP that uses a diaphragm-displacement pump and the parts list shows a "pulse Nipple" for $22. in the location that I have a pulse limiter. Why are they showing a pulse nipple and not a plug? Doesn't the diaphragm type pump get it's pulse from the 3rd hole at that pump mount location? Unless someone can advise otherwise I plan to plug the old pulse limiter hole & mount the diaphragm-displacement pump. Any thoughts are appreciated.
 

ANGEL-1

Cadet
Joined
Feb 5, 2010
Messages
12
Re: VRO conversion to Diaphragm-Displacement Pump

I have done some more research this morning which hasn't answered my question. My shop manual which covers 40-55 HP shows a photo of a manual start model and the diaphragm-displacement fuelpump has 3 hoses connected. one hose is the in line, 1 for output but the 3rd hose for what? ...does the 3rd hose go to the pulse nipple? If that is correct fine, but why can 't I find a fuel pump on -line to purchase with 3 hose connections ( they all have 2)?
 
Joined
Oct 22, 2007
Messages
2,598
Re: VRO conversion to Diaphragm-Displacement Pump

In an effort to simplify the fuel system ......

Is there some reason you believe your VRO pump isn't working properly? If not then it seems that you're wasting time and money on a non-existant problem. There have been several articles explaining how the VRO pump works and debunking all the old-wives tales about them.
 

boobie

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Nov 5, 2009
Messages
20,826
Re: VRO conversion to Diaphragm-Displacement Pump

If the vro is still pumping fuel I'd just leave it, disconnect the oil system and use 50:1 premix. Saves $$$$$$$.
 
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