Re: QD 19 Johnson, excess oil and fuel in water

[frankr]

Let’s start by realizing where the stuff is coming from. Every morsel of oil that you put in the gas goes through the engine. Some of it burns (smoke), and the rest goes out the exhaust–into the water. That is just the way it is, in any two-stroke motor. So why more in one motor than another can be several causes.

Incomplete combustion would have to be #1. Is it set too rich? Are both running the same mix, including same brand of oil?

Crankcase drains were mentioned. I believe both of those motors have the same drain systems. They drain off the fuel that settles out of the fuel/air charge as it passes through the crankcase. That drainage goes directly to the lake, without passing through the cylinders. Again, that is just the way it is. But one may be producing more drainage than the other one, for some reason that I don’t know.

Neither of those have the thermostat-controlled cooling system that came out later, so that isn’t it. Nevertheless, do they seem to be running about the same temperature?

Finally, the exhaust housing was changed between the 1957 and 1958 model years. That brings up an interesting thought. Does one get rid of the stuff by heat or wash-down differently than the other? For sure, it does, but how significant might that be? Something to wonder about