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Author Topic:   VRO Pump
Pops posted 02-14-2002 02:04 PM ET (US)   Profile for Pops   Send Email to Pops  
I just had the motor checked out on the Montauk I want to buy. It's a 1992 90hp Evinrude. FYI The VRO pump had been disconnected. The compression was 130,130,130 and 125.
Should I be concerned about the 125?
The lower unit on the motor checked out fine, "not sure what that means exactly, but I guess no moisture and good vacuum seals".
BUT the mechanic said the VRO pump is not pumping fuel correctly, he said it is spitting fuel. I thought that the VRO pump was just a oil pump and that there was a seperate fuel pump. Does the VRO pump actually handle fuel and oil? any help would be most appreciated.
ps the machanic said the motor needs a new VRO pump for $225 and about 1 1/2 to 2 hours labor at $64 per hour.
Bigshot posted 02-14-2002 02:33 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Compression is great.

The VRO and fuel pump are the same unit. You can block off or replace the fuel pump with a non-VRO pump. This is a very simple job and should take 1/2 hour if just doing a non-VRO fuel pump. It could also be a bad diaphram which costs about $10 and take 10 mins to fix. If it has all the VRo stuff like tank, etc tehn you might want to make it VRO again but I would look into where it is leaking and see if you can fix that first. Either way it is easy and by no means a reason to shun that rig. Use it as a negotiation tool.

WSTEFFENS posted 02-14-2002 03:06 PM ET (US)     Profile for WSTEFFENS  Send Email to WSTEFFENS     
Fix it. The VRO pump is a mixer powered by crank case pressure pulses. You also have a fuel (lift) pump that feeds the VRO unit which has a screen and diaphram in it. This is bolted to the crank case and is also powered by crank case pressure pulse power. It is located down stream from the plastic filter bowl (disposable) inside the engine housing on the port side of the engine.

I have had 4 engines since the mid 80's with VRO and they all worked well. The only failures I had was when a marina pumped me a tank of gas with an extream content of methonal. That fried the pumps and gas lines. All other failures that I have kowledge of were the result of bad maintence, loose hose fittings and cracked vacuum and fuel/oil lines. This would allow the engine to lean out or get a air block in the oil supply line and then "pop goes the power head." All riggers in this area mounted the oil tank (usually a 1 gallon version) in a BW battery box opposite the battery. This allowed for easy spill control during refilling and was effective camaflage.

Most who will tell you to disconnect the unit would also tell you to unpug the airconditioning compresser in your car in the winter to save money; and then not understand why the defroster/defoger for the windshield didn't work as it should.


Bigshot posted 02-14-2002 04:11 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I would not go that far. Many disconnected them due to fear of failure. I always used them with no problems. If it is already disconnected(which it is) there might be a reason for it. On a 90 mixing gas & oil is no big deal. On a V6 it gets expensive.
David Ratusnik posted 02-14-2002 04:27 PM ET (US)     Profile for David Ratusnik  Send Email to David Ratusnik     
If it were me I'd just pre-mix the oil and forget the VRO in a 10 y/o engine. It's an accident waiting to happen. My .03 David
Pops posted 02-14-2002 04:41 PM ET (US)     Profile for Pops  Send Email to Pops     
I'm not planning on reconnecting the VRO pump. What about the compression #'s, ok or very good?
Clark Roberts posted 02-14-2002 06:24 PM ET (US)     Profile for Clark Roberts  Send Email to Clark Roberts     
Pops, compression is ok!
bdb posted 02-14-2002 09:09 PM ET (US)     Profile for bdb  Send Email to bdb     
If you don't want to do the VRO thing, then replace the VRO-linked fuel pump with a simple diaphram pump. This eliminates the VRO linked fuel pump from "trying" to pump oil and fuel. Then you can run a simple pre-mix oil/gas supply.
Steve Leone posted 02-14-2002 11:51 PM ET (US)     Profile for Steve Leone  Send Email to Steve Leone     
pops, might want to do a cylinder leak down compression test. i bought a 70hp johnson one time that had 145lbs in each cylinder. could`nt get it to run right and it was very hard starting. took the head off and lo and behold there were some ugly scores on the cylinder walls. not paranoid, just careful. steve out.
commodore posted 02-15-2002 07:53 AM ET (US)     Profile for commodore  Send Email to commodore     
I had a new powerhead put on my 1986 Evinrude V-4 90 HP, and the OMC dealer also put a new VRO pump on. He would not bypass the pump, so I had a mechanic do it. I am now mixing the oil and gas in the tank without worrying about pump failure. However, I have been told that under this scenarion, I should replace the VRO pump with a mechanical pump, so as not to cause a vacuum. If someone agrees, or has done that, can you comment?


Whalerdan posted 02-15-2002 08:01 AM ET (US)     Profile for Whalerdan  Send Email to Whalerdan     
Could one go to some type of electrical fuel pump or would the pressure be too high for the float shut-off to work?
Pops posted 02-15-2002 09:22 AM ET (US)     Profile for Pops  Send Email to Pops     
I wanted to update you all on the Montauk I was trying to buy. The deal fell apart last night, the seller and I are 1k apart on price after considerable negotiations. I guess I will continue searching.
witness posted 02-15-2002 09:51 AM ET (US)     Profile for witness  Send Email to witness     
Hey Pops, Sorry to here that your deal fell through, maybe you should post in the Marketplace section exactly what your looking for... year and condition condition range, as well as intended use and location... Just a thought, Mike
Steve Leone posted 02-15-2002 11:31 PM ET (US)     Profile for Steve Leone  Send Email to Steve Leone     
there is a kit available from Bombardier O.M.C. to convert the existing vro to a conventional pump. steve out.
bdb posted 02-16-2002 08:13 AM ET (US)     Profile for bdb  Send Email to bdb     

Your question is exactly what I was referring to in my post above. I wasn't aware there was an OMC retro-kit (see above). However as I said above, a simple diaphram replacement pump does the trick. DO NOT try to just disconnect/plug the VRO oil inlet on the old pump.

commodore posted 02-17-2002 09:58 AM ET (US)     Profile for commodore  Send Email to commodore     
Steve, any idea of the cost? Part # (if universal)?


Steve Leone posted 02-17-2002 12:16 PM ET (US)     Profile for Steve Leone  Send Email to Steve Leone     
basically the price of a fuel pump. will get the peticulars tomorow, steve out.

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