I am considering buying a 1991 70 hp merc, oil injected. I dont know anything about merc's. Anybody know if this was typically a good motor, and a good year, or one to stay away from?
I personally don't like oil injected motors since the oil unit can fail and burn your motor up.<br />There are many who have no problems with it.<br /><br />Make sure you bring a compression tester and check the compression on each cylinder. There shouldn't be more than a 15psi difference in each cylinder.<br /><br />Look at the powerhead and see if any of the paint has been burnt off. If it has then the motor has probably been run hot.<br /><br />Have the guy run it for you and ask him if the water pump has ever been changed. Look at the stream of water coming out of the "tell tale" and see if it it has a good stream.<br /><br />Ask if the motor has been run in mostly fresh or saltwater, as saltwater can ruin the motor if it has been sitting and not been flushed out with fresh water.<br /><br />Hope this helps.
