---

Hello,
I have a 1997 Mercury 40 hp 2 stroke. Yesterday when launching I noticed a fuel slick in the water and liquid visibly spewing out of the two ports at the rear of the engine. When I took the cowling off I noticed some fuel in forward part of the "belly" of the engine. I have not noticed this before but I usually don't pay much attention to the water when launching and starting the engine.

When I got home, I flushed the motor on the muffs and the fuel/whatever wasn't spraying out of the rear ports anymore, but did notice the water going into the drain had a rainbow tint to it (tainted with gasoline)? I have not noticed this before but have not paid attention to the tint of the water when flushing.

The question is: do I have a problem or is this normal unburned fuel escaping from a 2- stroke motor?

Should I just take it in to the shop and have them check it out?


-Thanks!

---

You should never have fuel escaping from the engine. You will get an oil sheen but you have fuel visibly exiting the engine, I would drag that off to your local mechanic

---

The rainbow Sounds like oil. Was this the first launch of the season? Did you winterize it yourself? Often fogging oil is sprayed on the engine while winterizing, and if this was your first launch, you can have an oil sheen. Also, did it take a lot of cranking to start the engine?

---

This was about the 4th launch of the season (all within the past week). However, as mentioned I have never paid attention to the water surrounding the water on previous launches.

I usually crank it on the hose at the house to warm up the engine before we go. Cranking when cold is sometimes a challenge but at the boat ramp it fires right up.

The disturbing thing was the spray coming from the two rear facing ports just below the cowling. Never seen that before, and it wasn't doing that on the hose when we got back to the house.

I fired it up on the hose again today. Cranking took more effort than normal but it eventually turned over after about 6 tries of 5-10 second cranks. No spray coming from the ports below the cowling but the rainbow tint to the water coming out of the hub was still evident.

---

Was the "spray" from the rear exhaust ports on the engine "pulsing"? I think that is just normal cooling water, not pure fuel. When you are operating at higher throttle speeds - that spray will turn into a little waterfall as water pours out. It means your water pump is working very well. The volume of water available from a water hose is not great enough (often) to do this. YOu might also notice a weaker "pee" stream when running the motor on the hose at home. That's normal too.

However....if you have unburned fuel spilling out in the bottom cowling/pan area, you might have a leaking fuel line on the engine. I would remove the cowling and squeeze the primer bulb. While squeezing the bulb, inspect all the hose fittings on the powerhead and under the cowling for leaks. On an older Merc that I own, the hose fitting into the fuel pump had a small crack in it and it leaked fuel when you primed the engine...that is an easy fix for a shade-tree mechanic - or you can have your dealer fix it. It is important to find leaks from a safety perspective because of the danger of uncontained fuel, but it is also dangerous to your powerhead since fuel leaking out often means air leaking in - and that can really lean your mixture out and burn a cylinder requiring a rebuild...

---

Buckda, Yes the spray was pulsing. Could have been normal cooling water, but I have never noticed that before. Also, I think I remember the spray having the rainbow tint. Would that be normal as well?

Something was amiss as evidenced by the fluid inside the engine cowling (not pooling, just looked like a good misting/dowsing). I guess I got a little spooked at all of the rainbow in the water since I have never noticed that before.

What I am reading is that it must be normal 2-stroke engine emissions.

---

It's normal for an older 2 stroke to have a small oil like sheen behind it on the water....