Re: Oil injection system functioning on 1991 50 HP Merc?
I find that Pennzoil Premium TC-W3 smokes very little. Sea Foam is a fuel additive that does an excellent job of keeping engines clean and is very well suited for 2 strokes. Usage is recommended at 1 oz per gallon. Pint bottle sells for about $7 to $10 depending on store. I'd use it at the ratio of 2 oz per gallon till you get things straightened out. With that combo you shouldn't have any problems in the engine.
On does your pump work or not, you can sign up for the Seloc service manual onsight, upper right corner of this page. In there should be the directions for determining the pump operation. Basically it's real simple. You disconnect the output of the pump and with your pre mix in your tank, measure the output of the pump at 700 rpm for 15 minutes, accurate rpms and timer and then stop the engine. In my manual (OEM but I have Seloc subscription also) which is for the following engines it states: For the 3 cyl engines of 75 to 90 hp the container should hold 18.7 cc of oil. For the 4 cyl of 100 to 125 should be 25.5 cc. Test is run at 70F and it states that if temps are above or below LESS oil will be discharged.
So a quick extrapolation from the 100 hp engine would be half 25.5 cc or 12.75 cc for your 50.
Or the rule for fuel consumption used by a lot of knowledgeable people on this site is 10% of your hp in GPH at WOT. So a 50 would burn 5 gal at WOT. 5 gallons is 3785 cc/gallon x 5 gph = 18925 cc if gas per hour.
The test is run for 15 minutes (1/4 hr or 1.25 gallons) and at 700/5000 WOT rpm for (14% of WOT) with a mix of 50:1. So crunch all those numbers: 15 min is 1/4 hr or .25 x 18925 cc = 4731 cc, run at 700/5000 = .14 % WOT rpms, = 662 cc gasoline/50:1 oil mix = 13 cc oil.
So both numbers come up with the same answer (about 13 cc of oil) and I am comfortable with the numbers.
If you don't have something that measures cubic centimeters of that amount, go to a drug store and get a throwaway plastic cup.
HTH,
Mark
