Vro Problem

nickjack69

Cadet
Joined
Apr 30, 2009
Messages
9
1998 50hp Evinrude. The Vro Pump Is Pumping Way To Much Oil. The Bowls Of Both Carbs Are Full Of Oil. Is There Any Way To Test The Pump? Or Do I Just Need To Order A New One?
 

Phoenixfirewalker

Petty Officer 3rd Class
Joined
Jun 18, 2009
Messages
94
Re: Vro Problem

what we do on this side of the world is we eliminate the vro and mix the oil in with the fuel.
why? because in the same manner it is pumping to much oil now maybe next time it pumps too little or no oil.
and...
guess what?
you'll find out when your engine is ruined!!!
thats why we eliminate the system period!
just mix oil into gas tank using a $2 measure jar available in your boating goods store or walmart
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Vro Problem

It's quite possible that nothing is wrong with that VRO. If a fuel restriction exists, this would result in more oil than fuel being delivered to the carburetors due to the fact that the unrestricted oil diaphram side of the VRO would be pumping the proper and normal amount of oil with each crankcase pulse.

So, before you shell out a few hundred dollars, check for a fuel restriction first, the most common one being as follows:

(Fuel Anti Siphon Valve)
(J. Reeves)

Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vacuum device attached to the powerhead. If the engine overheats, or if you have a fuel restriction, the warning is the same.... a steady constant beep.

NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models.

The fact that a engine is not overheating, but the warning horn sounds off with a constant steady beep, and that the rpms drop drastically would indicate that the engine is starving for fuel due to a fuel restriction. Check the built in fuel tank where the rubber fuel line attaches to the tank fitting. That fitting is in all probability a "Anti Siphon" valve which is notorious for sticking in a semi closed position. It will be aluminum, about 2" long, and the insides of it will consist of a spring, a ball, and a ball seat. If this valve exists, remove it, knock out those inner components which will convert it to a straight through fitting, then re-install it. Hopefully that cures the problem.

The above procedure will cure a restriction problem with the anti siphon valve as stated. BUT, it may also allow fuel to drain backwards to the fuel tank when the engine is not running (siphoning backwards) due to the fact that the carburetors/fuel pump etc are higher than the fuel tank. This condition is not an absolute as the valves in the fuel primer bulb usually prevent this backwards siphoning problem. However.... if this does take place, the cure would be to install a new anti siphon valve.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Vro Problem

i the oil tank, higher than the carbs, had this problem with my pontoon. the oil would siphon into the carbs when the motor was setting for a period of time.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Vro Problem

Seen this on many pontoons with the fuel line left connected over the winter.

Clear/flush the carbs by pulling the float bowl drain and pump the primer bulb until clean fuel drains out. Do one carb at a time.

Start disconnecting the fuel line when not in use.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Vro Problem

it is not the fuel line that is the problem, it is the oil line.
 
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