butch

Butch Money

Recruit
Joined
Nov 17, 2008
Messages
1
My son just purchased a 1985 75 hp Mercury outboard motor that has been sitting up for a while. We will need to get someone to do some work on it I"m sure, but we would like to try to start it first. We have been told that it may have an oil pump or we may have to mix the fuel. Does anyone know and do you know what the mixture formula is? This is probably simple to you guys, but we are novices and could really use some advice. Thanks so much.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: butch

Two stroke oil injected engines have an oil tank on the motor or a remote mounted tank. You need to add two-stroke oil that has "TCW3" on the label. DO NOT use two-stroke lawn mower/chain saw oil. If the oil resevoir is gone then the oil injection system has been removed and you will need to mix one pint of TCW-3 oil with every six gallons of fuel which equates to a 50:1 ratio. If the oil tank is still there, and there is oil in it, chances are the system may still be intact but you will need to determine if it is functioning properly. Until you determine that, pre-mix fuel as I indicated, Then place a mark on the oil tank to mark the oil level. Run the boat until you've run through about six gallons of fuel. The oil level should have dropped about one pint. Add one pint. If that brings the level back to the mark the system is functioning and you no longer need to mix the fuel. If the oil level did not drop, then the system is not working and you need to continue to premix. During this testing period, the engine may smoke more than normal if the oil injection system is working as it would be getting twice the amount of oil it needs. It does not affect the engine. Too much oil is better than none at all.
 
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