Noticed oil inside bottom of engine cowling...

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
1986 Merc. 175...<br /><br />At first I thought this was a result of the removal of the oil injection system and a little bit of left-over oil in the resevoir tank... But after closer examination the oil appears to be thinned down probably left from evaporated fuel... Can the carbs or pump release fuel if over primed or choked... If not, where should I start looking for a likely source for a leak...<br />It's not a huge leak, but enough to coat your finger pretty good after performing a white glove test on the bottom inside of the cowling.
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
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2,177
Re: Noticed oil inside bottom of engine cowling...

Check the cover where the oiler used to be. Also check to see if the hose from the bottom of the air box is hooked up.<br /><br />And of course..fuel lines ect.<br /><br />TMD
 

KCLOST

Commander
Joined
Jun 22, 2002
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Re: Noticed oil inside bottom of engine cowling...

Thanks TMD... Air Box? That's a new one to me..<br />Can you help me locate?<br /><br />And, do you see a problem with me power washing the engine, I'd like to clean it up prior to running it to find the leak.. Any electronics I need to avoid?<br />Thanks
 

trumanlake

Petty Officer 2nd Class
Joined
Aug 8, 2003
Messages
131
Re: Noticed oil inside bottom of engine cowling...

just for grins, have you checked all of your bleed hoses?(cracks, or broken) we had noticed oil on inside of the port side cover, found one hose had came off.
 

andrewkafp

Lieutenant Commander
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Mar 15, 2003
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1,668
Re: Noticed oil inside bottom of engine cowling...

Whenever the carbs are flooded (Priming etc), there is always some fuel/oil mix discharged. When the petrol evaporates, oil is left. I notice this even at my fuel fittings if I leave them in the transom engine well, still connected.<br />It doesn't take long to accumilate a few ml of oil over a few days. You motor has no oil in it, so it's gotta be the pre-mix.
 

ronmold

Petty Officer 1st Class
Joined
Sep 8, 2003
Messages
240
Re: Noticed oil inside bottom of engine cowling...

"Foamy engine Bright" engine cleaner worked good for me. Get it at Wal-mart etc. Just spray it on, let it soak 15min and wash it off w/ hot water. Pressure washers can force water into places you don't want it to. Works on the foam rubber sound blankets in the cowl too.
 
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