Re: 50:1 Cheap Insurance?
I have an '89 100HP Merc that I debated about this also. What sparked my worries was one of the plastic lines (that carries oil from oil tank to oil pump and from oil pump to fuel pump) breaking one day. Even though the oil pump continued and no buzzer sounded, I was losing partial (thank heavens not all) oil before it got into the mix. I caught it quick and did a compression test and no damage. But that sure got me to think also...<br /><br />Then I talked with as many folks as I could and I found that some of the bass fisherman were also trying to make sure they were protecting their big expensive motors by adding a little extra oil in case of pump/line failure.<br /><br />When I read the particulars of my '89 Merc oil pump in the Merc service manual I realized it ran at 50:1 only at WOT. At idle, my motor runs at 80:1, and the ratio is continuously variable from 80:1 at idle to 50:1 at WOT. <br /><br />Realizing I hardly ever run at WOT more than a few seconds to a minute or so to pull a skiier up, I did some calculations and my decision was to add one extra pint of 2-cycle oil to the tank for each 12 gallons of fuel I add. So, at idle, I'm still no more (or not much more) than 50:1 and at normal cruise I'm still in the ballpark of 40:1 - 50:1. I also run Merc QuickClean at 1-2 oz per 6 gals as recommended by my dealer, so the engine is constantly being cleaned. <br /><br />I've been doing this for 3 years now and the motor is doing great and I sleep a bit better knowing that if an oil line breaks again, hopefully I'll see a temp increase before I lose that powerhead...<br /><br />Many may disagree with this, but after thinking about it for a long time, it's what I decided to do...
