hey guys, I have a question about my first boat.... It has a 115 Johnson fast strike with oil injection..  would you bypass the oil injection and mix the gas yourself to prevent a problem in the future?  Also, would you recommend adding a little oil to the gas in combination with the oil injection system.... the owers manual states that when high performance boating, whatever that is, to add oil 50:1 to the gas in combination with the oil injection... Any help would be great as this is my first boat.......thanks   darren

I just bought my first boat as well.  It has a 50hp oil injected Evinrude.  I asked the local Evinrude dealer the same question.  He sugggests adding some oil to the gas in addition to the injected oil.  He said it can't hurt but is actually good for the engine.  Worse case, it may smoke a little.

You can also draw a line on your oil tank marking the level of oil.  Make sure the oil is dropping.

He said when you start the motor, you hear a chirp.  This is the system check to make sure the oil injection is working.  

good luck

Larry

Ive got a 150 Johnson Fast Strike, and I have disconnected the oil injection and mix it myself.  Trust me, on the blown motor, 5 extra minutes of mixing is def worth it over paying 5000 dollars fix the problem.  Also do not oil it too heavy because you can fowl out your plugs if they get to much oil.

I would like to here other peoples opinion on this also. I have a 50 horse Yamaha oil injected and have never really given it a thought about just mixing the fuel. I was happy that I didn't have to mix it. Maybe I should be thinking differently. What does everybody do that has oil injection???

Doug

I think its recommended that you replace the VRO pump every 5 years. I'd personally rather pre mix at 48:1 or 50:1. And decab once a year.

If your OMC motor is older than 1999, I would recommend replacing the VRO with the updated CRO.  In 99 the made changes that did away with the variable ratio oil and also made them much more reliable.   Just be aware, a new pump cost approx $300 plus labor.  Another problem I've see a lot is water in the oil tank.  I would recommend dumping the tank and cleaning it.

As for whether to run oil pump or premix, that's a presonal thing.  On my hot rod motors I'm turning 7,000 rpm I premix @ 40:1.  On my stock motors turning 6,000 or less rpm I prefer the convienence of oil injection.

So, my feelings are, if your running an older OMC with a pre 99 pump, unplug the wires going to it and the oil tank so they don't set off the alarm and premix @ 50:1 to be on the safe side.  If there is a lot of oil in the tank, might want to wait until it's low, so you won't be double oiling.  Unpluging the wires going to the pump doesn't stop it from pumping, just keeps the alarm from sounding, it's still going to pump oil until the tank goes dry.

As for high peformance applications, don't premix 50:1 with the oil injection connected, only premix 100:1 under those conditions, 50:1 is way too much oil and despite what was said, can hurt the engine.  It will double the carbon build up, it also make the pistons hold more heat.  On a fairly tight engine, this can cause them swell enough to make them gall the skirts, and stick.   The whole stock fuel system is only rated for about 6,500 rpm anyway.