Merc Optimax 225 (2005) leaving oil slick

[SeLaOffshore]

I have 2 (2005) Mercury Optimax 225 Outboards on my boat - of the 2 stroke variety. Both motors leave a small oil slick on the water whenever I initially put the boat in the water and whenever I shut the motors off. I've brought the motors to 2 different mechanics for other repairs, and asked them to investigate the cause of the slick and both say the situation is normal and "It just happens when the motors get to be that old." I'm not satisfied with that answer and logically conclude something is wrong that should be fixed. It's really hard to pinpoint the source and while it seems to be coming from the exhaust, I would not be shocked to learn that the oil is coming from a cooling jacket in the lower unit. Can anyone offer suggestions to diagnose and resolve this issue?

 

[dingbat]

i hate to be the bearer of bad news, but it's normal.

With no emission controls in place, any unburnt fuel and oil from the previous compression stroke is simply blown out the exhaust ports unhindered. The reason why most two strokes are banned on a large number of lakes.

Remedy? Sell it and buy a 4 stroke or an E-tec

 

[SeLaOffshore]

What I don't understand is................ It only started doing this recently. So I ask myself "What has changed?" in other words - What has worn out that I can replace to stop the slick? Replacing the motors is not an option, as a retiree on a fixed income, I simply can't afford to plunk down upwards of $40k to stop a very minor oil slick. And I've been running a variety of outboard motors since the early '60s, long before emission controls were the thing, at least a dozen different 2 stroke motors in those 50+ years both on my own boat and boats owned by friends, I've never seen this situation before.

 

[rjcamel2355]

Every outboard I've owner, or seen, aside form e-tec or fourstrokers does the whole oil/gas slick... like Dingbat said, it has to do with unburned fuel/oil being spit out.

 

[Chris1956]

Gee, I don't agree. Optimax motor are low emissionmotors. My neighbors never leaves an oil slick.

Those Optimax motors pump oil into each cylinder and also the air compressor. Excess oil from the compressor is routed to the upper main bearing. I would start by tracing the oil lines from pump to oil manifold and to each cylinder and the compressor. Next find oil line from compressor to main bearing. See if you can find the leak.