Gray matter

hogtamer

Cadet
Joined
Jun 11, 2001
Messages
10
I have a 15hp Johnson oyerhauled last year I troll with it all day, at the end of the day gray sludge comes out of the lower unit and it gets the tansom all oily The motor runs very good I was told this is normal I say BULL Iuse TW3 oil 50 to 1 Is there a gasket bad ? Some days alot comes out,other days not much.
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Gray matter

Where does this gray oil come out at? Behind the prop? Out of the exaust ports?<br />Idling all day will create abnormal amounts of unburnt fuel/oil mix. It should noramlly foul the plugs more often than usual too.<br />Impeller wear is higher then normal if an outboard only idles. This is due to the vanes making constant contact with the pump housing walls. Not a biggy, but the impeller is a wear item to begin with, which is why I brought it up.You may want to change it every season.<br />To make sure your lower unit is ok, check it at the vent screw,using a pipecleaner like a diptick. IT should be full to the top, and translucent olive green,or brownish green.<br />If it is gray, you have a bad seal in the lower unit....Either prop seal,driveshaft seal, or both. Always remove the old screw gasket, and use a new one each time you check it.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Gray matter

Hi, Hogtamer. How much throttle are you using to troll? Most 2 strokes hate to idle under light/no load for long periods and will load up the exhaust with unburned oil where it mixes with cooling water to make a grey or brown (UGLY STUFF!!) sludge. That stuff looks a lot like what you will get in your lower end if water gets in there. Had that problem years ago and solved it by (surprise!!) using a smaller motor (2hp) for trolling. By working harder it ran cleaner.<br /><br />Smooth waters.<br />JB
smile.gif
 

ODDD1

Lieutenant Junior Grade
Joined
Jan 23, 2001
Messages
1,054
Re: Gray matter

yes is what used to be premix oil/fuel....try running the kicker wot before you shut it down to clear out some of it.....
 
Top