Power Loss - intermittent '86 Johnson 90 Also.how to disable VRO?

Steve45

Cadet
Joined
Feb 28, 2003
Messages
6
Hi<br />1. This is a great forum...tons of good info. Seems like power packs etc. are a common OMC problem. Was wondering if the following scenario fits the bill. Have an 86 Johnson 90 HP V-4 with the VRO. Very rarely it loses power at WOT. Runs great at idle and revs up great in neutral. Put it back in gear and it runs perfect for hours before it happens again. Sometimes it dies for only a second or 2 then comes right back to life on its own.<br /><br />2. Also...there seems to be a lot of opinions in the forum that the VRO is the cause of a lot of trouble. Mine has been replace once. If I chose to disable it, what is the proper way to go about doing that?<br /><br />Thanks in advance for anyone's advice!
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Power Loss - intermittent '86 Johnson 90 Also.how to disable VRO?

Steve.... YOu may be encountering a fuel restriction occasionally which may affect the WOT range. Check the following anti siphon valve info. There is also advice on removing the VRO following that.<br /><br />(Fuel Anti Siphon Valve)<br />Many of the later OMC V/6 engines incorporate a fuel restriction warning via a vaccum 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.<br /> <br />NOTE... Only the V/6 & V/8 engines have the above "Fuel Restriction Warning". The warning horn will not sound on the other models. <br /><br />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.<br /><br />-----<br /><br />(VRO Pump Conversion To Straight Fuel Pump)<br /><br />You can convert the VRO pump into a straight fuel pump, eliminating the oil tank and VRO pump warning system, but retain the overheat warning setup by doing the following:<br /><br />1 - Cut and plug the oil line at the engine so that the oil side of the VRO pump will not draw air into its system. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.<br /><br />2 - Trace the two wires from the oil tank to the engine, disconnect those two wires, then remove them and the oil tank.<br /><br />3 - Mix the 50/1 oil in the proper amount with whatever quanity fuel you have. Disconnect the fuel line at the engine. Pump the fuel primer bulb until fuel exits that hose with the tint of whatever oil you used. Reconnect the fuel hose.<br /><br />That's it. If you want to test the heat warning system to ease your mind, have the key in the on position, then ground out the tan heat sensor wire that you'll find protruding from the cylinder head. The warning horn should sound off.
 

Steve45

Cadet
Joined
Feb 28, 2003
Messages
6
Re: Power Loss - intermittent '86 Johnson 90 Also.how to disable VRO?

Joe<br /><br />Thanks for your response...I will check out the fuel lines at the tank tomorrow and will let you know what I find. Appreciate the advice!<br /><br />Steve
 
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