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.