Oil coming from the exhaust

simtal

Recruit
Joined
Oct 10, 2015
Messages
2
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Recently bought this older 9.9 Mercury outboard, has been running fine since last week although today after a good run it stalled and now it is running rough - revving up and down and now I've noticed what seems like oil coming out of the exhaust. I didnt know what ratio to mix the 2 stroke oil, perhaps thats the issue? 25:1, 50:1?

Thanks for any help in advance!

Cheers,
simtal 20151010_183943.jpg
 
Last edited:

fhhuber

Lieutenant
Joined
Jun 19, 2014
Messages
1,365
Excess oil eventually fouls the plugs and ... you're done until you put in new spark plugs.

I don't know the mix for that engine, but i expect close to 40:1 or 50:1.

Penzoil Marine 2-stroke oil has been great in my old Johnson 150 (pre-mixing because the VRO is guaranteed to fail) Low quality oils can cause issues with fouling the plugs also.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
+1 on both responses. The Pennzoil sold at WM in the sporting goods section is synthetic blend and at the 50: 1 ratio makes for little smoking with fresh regular grade gas. Pull one of your plugs and go to an auto parts store and get new ones. NGK plugs run good in Mercs and are the OEM plug for new engines. While you are there pickup a can of Sea Foam in the auto section and follow the directions on the can. Add this in addition to your 50:1 mix, does not change that ratio.
 
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