Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Mercury 40 HP oil injection questions

Posted by burtim on 04/21/08 - 8:43 AM
#1

Hey folks,

I ran my 2001 Mercury 2 stroke 40 HP this last weekend and noticed that it used what I thought was very little oil. The motor has about 35 hours on it since new in 2001. In other words, it hasn't been used much and I've only had it on the water four times.

I filled the reservoir completely yesterday and ran it one hour at between idle and 2,000 to 3,000 RPM on the lake. After the hour I had to put about 2 gallons of gas in the tank. The oil reservoir hadn't emptied below the filler neck. Does that seem normal?

I don't have much experience with these motors and they don't seem to need much oil if this is normal. Is there something to look for and/or does the oil injection go bad on these (especially if they haven't been used much).

Posted by moose on 04/21/08 - 9:01 AM
#2

Is your motor infected or carbed? I don't know how much difference it will make but the oil consumption is much less at lower rpms.
Mike

Posted by Gary Sr on 04/21/08 - 9:42 AM
#3

Most of these engines run about 100/1 gas to oil mixture. If you used 2 gals of gas this calculates to about 2.5 oz of oil. Your filler neck would probably hold only a few oz of oil.

Posted by burtim on 04/21/08 - 2:17 PM
#4

The engine is fuel injected. If the mixture is 100:1 that would make sense. I put a small amount of oil in the fuel tank in case there is a problem. Better some than none!

Back to the question though. What would be the symptoms and have people on this list seen loss of oil injection on Mercruy two strokes?

Posted by moose on 04/21/08 - 2:42 PM
#5

I'm not sure about that engine. I think some of the injected Mercs are the same as the Nissan, or at least use the same technology. The oil injection varies with the rpm because at low speeds it doesn't need the same lubrication that it does at wot. With premix you have to mix at 50:1 to cover the wot operation and then at idle and slower speeds you have way too much oil.Mine (Nissan)doesn't smoke at all and used very little oil. I run at cruising speed most of the time and some times faster with an occasional wot. It seems to use about the same amount of oil as if I had been premixing.
A note of caution. I would check with a pro before adding iol to your tank. That may not be good for your injectors.
Mike