2005 9.9 Mercury 2 Stroke outboard oil discharge?

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abk

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Aug 9, 2007
203
Hunter H 26 Somers Point, NJ
Wrong dilution posted, not 25%, 25:1 oil/gas mixture used.

I bought a new, unused Merc (2005) 9.9 2 stroke and it leaked oil after running a 25% gas/oil mixture for the break in period. After a run on my sailboat, I returned to the dock and it was discharging oil from a small hole on the starboard side just above the lower end.

I thought it was gear oil. I took it to a dealer (merc) and after a $130 assessment they said it was engine oil and it was due to running the oil rich mixture. The removed and pressure tested the lower end. They said it was ok and looked like a new engine.(it is)

Well, it happened again with a regular mix.

Any ideas or info on this condition would be appreciated.

I would like to know where and how and why the oil gets to this discharge "hole".

Thanks in advance.

Added a photograph... it is hard to see but look above the gear housing... Just above the line is a small hole...
 

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May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
If the lower gear case isnt leaking, the only place youll get oil is from the exhaust. The engine doesnt have any oil other than what is mixed with the fuel. Are you mixing it properly? 50:1 is 50 parts fuel to 1 part oil. Likely the oil your seeing after running less oil is only residual from the first batch. Keep running it, and run it hard those first few tanks, it should clear out.
 
Jun 2, 2004
3,498
Hunter 23.5 Fort Walton Yacht Club, Florida
Mine Does Too

Always has I thought it was unburnt oil making it's way out.
 
Nov 6, 2006
10,048
Hunter 34 Mandeville Louisiana
I agree with Anchor.That hole is a low point drain for anything that drips off the engine. although some (maybe most) can be coming from the carburetor vent or bowl gasket, or the fuel lines or fuel pump.. The stuff you are seeing is most likely residual from the 25% run (MAN that is a lot of oil!! is it 25:1 gas/oil ratio?) It will drool for a few days, most likely. You can take off the cowl (engine cold) and then connect the fuel line.. then pump the bulb as you normally would.. watch the carburetor and fuel lines and fuel pump when you pump the bulb to see if fuel/oil is dripping out anywhere.. I think the "dealer" may be taking you for a ride..
 
Jun 8, 2004
10,373
-na -NA Anywhere USA
Any two stroke engine is one where oil is added to the gas. The only other lubricate is the lower house lube and generally it could be from a loose fitting as there are two of them on the lower housing. Suggest that you follow the advice of Kloudie as you may be taken for a ride.
 
May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
If the dealer is who you bought the motor from, agree they may be shorting you, but then again we wernt there. If you bought it elsewhere all bets are off. $130 is like the minimum now many places.
 

abk

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Aug 9, 2007
203
Hunter H 26 Somers Point, NJ
It was not purchased from the dealer...

If the dealer is who you bought the motor from, agree they may be shorting you, but then again we wernt there. If you bought it elsewhere all bets are off. $130 is like the minimum now many places.
I bought it privately. he bought it for a dingy but it was to big and he stored it in his shed.

It was wrapped in it's original plastic and the gas tank was unused too.

I paid $750 and even with the repair bill I think I am still ahead of the game. I don't know how much it did cost new though.

The dealer did say it was run off from the exhaust and rich mixture.

About the break in... Mercury states run the 25% mix for a tank full. Not at full power and not at one sustained speed for longer than 2 minutes for the 1st hour of operation... So I did just that.

A Tank full? 3 gallons, 6 gallons? No one had an answer so I ran the heavy oil mix with a 3 gallon tank.

Thanks to all for your input too...
 
Jan 2, 2008
547
Hunter 33 (Cherubini design Forked River, Barnegat Bay, NJ
It is NOT twenty five pre cent that Mercury is looking for. It is twenty five to one mixture, whichis still double the normal mixture. You'lll occasionaly see raw oil from the engine at normal mixtures, so at a rediculous 25 per cent I would think so. You undoubtedly have oil separated out and sitting at the bottom of the crank case. To use the old expression, " run it hard and blow it out". It's the only way you will draw that oil out.
 

abk

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Aug 9, 2007
203
Hunter H 26 Somers Point, NJ
It was a 25:1 ratio, not 25%...

It is NOT twenty five pre cent that Mercury is looking for. It is twenty five to one mixture, whichis still double the normal mixture. You'lll occasionaly see raw oil from the engine at normal mixtures, so at a rediculous 25 per cent I would think so. You undoubtedly have oil separated out and sitting at the bottom of the crank case. To use the old expression, " run it hard and blow it out". It's the only way you will draw that oil out.

Sorry I did do the 25:1 ratio, not a 25% (1/4) oil to gas mixture... I posted the informaton incorrectly.
 
Jul 28, 2010
914
Boston Whaler Montauk New Orleans
ABK, do you have the manual for that engine? If not, as it is fairly new, you can probably get one from Mercury. In the meantime, see if you can see what the "hole" is connected to by taking off the cowling, as Kloudie said.

As for the oil, I recently posted a question in a fishing forum re outboards because I put too much oil in the mix (not double, but I was concerned). One of the guys, who has fished and messed with outboards for decades, said that the Merc racing teams he used to work with would double, and sometimes triple, the oil mixture to increase the compression. I wouldn't do that, but at least it allayed my fears. ;-)

One more thing - an easy way to remember how much oil to add is that for 3 gallons of gas, you need to put 8 oz of 2-stroke oil. (Don't get the cheap stuff from Lowes or Home Depot - get a proper marine 2-stroke outboard oil.)
 

abk

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Aug 9, 2007
203
Hunter H 26 Somers Point, NJ
I do have the manual... It shows the "hole" but there is no explanation of its function...
 
Jul 28, 2010
914
Boston Whaler Montauk New Orleans
I do have the manual... It shows the "hole" but there is no explanation of its function...
Haha! I won't touch that one!! In the manual, does it have an internal diagram that maybe shows another, possibly an internal, view of the hole that might give you some clues? Can you see the hole from the inside when you take off the cowling? Where on the motor is the hole?
 
May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
The hole is merely a drain. The dealer would have suggested something different if it were anything else, and its not. As far as oil mixture, it can often get confusing. Just remember that there are 128 ounces in a gallon. However many ounce bottle of oil, keep the mixing ratio 25:1, or 50:1. And always fudge to more oil rather than less. A pint of oil to a 3 gallon tank would be about 24:1, 8 ounces would be roughly 50:1. A quart to that 3 gallon tank would be pretty rich, about 12:1, and would smoke like an old chainsaw.

Remember to readjust the idle fuel mixture and idle speed as your breaking it in. Engines break in much faster today, better metallurgy, closer tolerances, etc., but you can extend the break in period longer and will generally end up with a better motor. The reason to keep moving the throttle is to extend the crankshaft bearing wear over the full timing advance range, not allowing the load to bear only on one point for any extended period of time. You need greater throttle to keep pressure on the rings so they seat faster and more properly. I would probably run at least two tanks through it at 25:1, then gradually thin it out, maybe reaching 50:1 by the 4th or 5th tank. No trolling or light throttle for any extended period until its fully broken in. Also good idea to pull the fuel line off while its running, after you dock, and run it till it quits.
 
Apr 22, 2009
342
Pearson P-31 Quantico
. . . it leaked oil after running a 25% gas/oil mixture for the break in period. . . .
Why not go back and edit your post to say, ". . . it leaked oil after running a 25:1 gas/oil mixture for the break in period. . . ?"

Just wondering.
 
May 16, 2011
555
Macgregor V-25 Charlton, MA- Trailer
I have the same problem w/ my Johnson 9.9 sailmaster. It is unburned oil. It actually oozes from the bottom exhaust holes in the bottom end. After much web surfing on the subject I found that this is normal. I even rebuilt the fuel pump because if the diaphragm is compramised fuel can go directly into the crankcase and further the issue. My motor was supposed to run 100:1!! I had a lot of motors in my day and that was too close to nothing at all. I ran 50:1 and had the oil discharge. I now run 75:1 and it is better but still there. Either dark black brown or tan puss. A good explanation of this problem and more is in the attached link. This link is teh best outboard motor link that I have found.

http://www.leeroysramblings.com/Ramblings.html#OMRA
 

abk

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Aug 9, 2007
203
Hunter H 26 Somers Point, NJ
Haha! I won't touch that one!! In the manual, does it have an internal diagram that maybe shows another, possibly an internal, view of the hole that might give you some clues? Can you see the hole from the inside when you take off the cowling? Where on the motor is the hole?
The hole is on the bottom of the engine above the gear housing. It is not the gear oil screws. It's just a small hole. It is 2 stroke oil.
 
Nov 6, 2006
10,048
Hunter 34 Mandeville Louisiana
OK, need semantics clarification.. I thought "..just above the lower end.." was the lower engine housing to which the lower end is bolted.. If so, then suspect carb drool and gasoline evaporates, leaving oil to run out of the hole just below the engine block.. If "just above lower end" means immediately above the gear housing in the lower leg, then I agree with unburned oil .. kind of a natural thing for two strokes to do, especially when running slowly.. My "dealer" comment is because any decent service guy can look at and smell and feel the oil and determine if it is gear oil or engine oil... without charging you $130.
 
Mar 26, 2011
3,670
Corsair F-24 MK I Deale, MD
ABK. Please get a manual on 2-strokes and read it. The oil atomizes with the gas in the carb, is sucked into the crankcase case where it is compressed by te desending piston and pushed into the cyclinder. Some of the oil condenses in the crankcase and drains out. This is a NORMAL polution source from 2-strokes and is a part of why they are no longer available in the US.

As for a $130 charge, he spent shop time on it and had to put it in a tank. I don't see the problem. If you had explained what you saw, he should have suggested it was normal, but if you wanted him to check, he had to confirm it was not the lower unit.
 
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