97 merc 40 two stroke grey substance

[Duk518]

I have a 97 merc 40 hp two stroke that has a grey substance coming from the prop area after I changed the lower unit gear oil. This showed up after running in the driveway with muffs for 10 mins.

 

[racerone]

fairly common sludge.----Not to worry.----But have your local friendly boat shop do a pressure test on the gearcase if you are worried.

 

[jimmbo]

Any shiny/sparklies in the sludge?

 

[QBhoy]

Seen this before, with it being 2 stroke oil residue from sitting in exhaust...especially on a too heavily mixed oil ratio.

 

[Scott Danforth]

you cant load the motor on muffs, so the unburnt fuel and oil become exhaust sludge

 

[racerone]

Loaded or not loaded.--------Some fuel / oil goes right out the exhaust ports and is wasted !

 

[The Force power]

Yup!! just check a test-tank after useainkiller: