# 2 stroke oil leak



## malisha1 (Nov 16, 2018)

Hi, I have a 2 cycle Murray 4.5hp single stage. I like it a lot and it works super well with no issues so far. I would like to continue to use it for a long time with basic maintenance. I have noticed that the bottom of the engine is covered with oil. I might be incorrectly mixing the gas and oil but I wanted to know if this is normal or is there an issue? There is no blue smoke exhaust when running


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## malisha1 (Nov 16, 2018)

Pix


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## crazzywolfie (Jun 2, 2014)

have you tried wiping it off and does it come back? there should be no oil leaking from the crank case if the engine is running good. the 2 strokes require the crank case being sealed to operate properly. maybe some gas has leaked out of the carb and ran down there. hard to say. those are good little machines. i used to have one and loved it.

edit it might be coming from the exhaust now that i looked at it again. sometimes they don't always burn all the fuel and it will come out the exhaust


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## RedOctobyr (Mar 2, 2014)

For a 2-stroke, blue smoke while running is really influenced just by how much oil you have mixed in the gas. Unlike a 4-stroke, a 2-stroke's smoke amount shouldn't really change to things like worn piston rings. 

It could be a worn/leaking crankshaft/crankcase seal, as crazzywolfie said. Or it could be a carburetor leak, that's allowing oil-mixed gas to drip down the engine. Then the gas evaporates, leaving just the oil. As he said, I'd clean it up, and see if it comes back. 

Are there any drips from the carburetor?


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## malisha1 (Nov 16, 2018)

Yes I did wipe it off and it returns. I suspect it's coming from the exhaust. In the pix I posted there a hair like cracks in the crank case. Could it be coming from there?


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## crazzywolfie (Jun 2, 2014)

if it is running good then it probably isn't a seal tho. usually 2 strokes won't stay running long if a crankcase seal is leaking. to me with how dark the stuff is it looks like it is coming out of the exhaust. maybe a bad muffler gasket. my old machine use to have the muffler vibrate loose all the time. i never cared about leaks so never paid much attention to that


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## RedOctobyr (Mar 2, 2014)

Can you point out the possible crack(s)? They might just be casting marks, hopefully. 

Some of my 2-stroke machines drip some oil from the exhaust. I'd imagine it's influenced by the oil mix ratio you're running, as well as what type of oil. My 2-stroke blower certainly has some oily residue on the plastic shroud by the muffler. Even if muffler gaskets were perfect, I'd imagine you could still get some dripping from the actual exhaust opening itself.


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## crazzywolfie (Jun 2, 2014)

but if the gasket was doing its job it would seal up between the muffler and block and burn up any oil/gas residue in the muffler or spit it out the muffler instead of having it leak down the engine onto the ground.


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## evh (Jun 22, 2015)

What ratio are you mixing the gas/oil? What you are showing is not totally unusual. I have worked on over 50 of there machines and typically there is oil in that area. Yours looks a little worse then what I have seen, however, you may be running too much oil.

I really would worry about it too much. Those engines are pretty hardy things. Again, how many ounces of 2-Cycle oil do your run to how many gallons of gas. It is a 50:1 ratio so that should be roughly 2.6oz per gallon of gas or 5.2oz per two gallons of gas.

You can also easily lift up the cover (remove 3 back screws and typically about 2 - 3 screws on each side and you can lift it and see the muffler and how much is leaking down the side of it. To remove the cover totally (vs just lifting it up), remove the top part of the chute and you can then slide the plastic cover totally off.


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## malisha1 (Nov 16, 2018)

I have taken the covers off and most of the oil was a round the exhaust. I usually mix 25-30oz of gas just enough for one gas tank bc I don't get too much snow in NYC I don't want to store 2 cycle gas bc I have no other machines that need it.


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## malisha1 (Nov 16, 2018)

This is the oil I use. I usually put two cap lids of that oil into a plastic bottle 25oz of gas and mix it well. The mix turns blue


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## RedOctobyr (Mar 2, 2014)

malisha1 said:


> This is the oil I use. I usually put two cap lids of that oil into a plastic bottle 25oz of gas and mix it well. The mix turns blue


Doing a more-precise measurement may be worthwhile. Both to reduce excess oil & dripping, and to ensure you're getting *enough* oil. 

You can use something like a small measuring cup from a cold-medicine bottle, etc. Or an old tablespoon measuring spoon, if you've got one you can get dirty. A 50:1 ratio is common, so you'd be looking for 1/2 ounce of oil, for your 25 oz bottle. That would be 1 tablespoon (2 tbsp = 1 oz). 

Even if you don't have a tablespoon you can sacrifice, you could measure out 1 tablespoon of water, and then see how that compares visually to your 2 capfuls. Maybe you're using too much oil. 

Oh, and if you end up with leftover 2-stroke gas, you can use it up in a 4-stroke machine. I've poured in my tractor's tank, etc. Some people put it in their car, though I prefer to use it another small engine, which doesn't have a catalytic converter.


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## malisha1 (Nov 16, 2018)

Well that's exactly what I did I used kids medicine syringe with water to measure .5 oz and covered that into caps. I need two caps for 25oz gas


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## RedOctobyr (Mar 2, 2014)

Perfect  Sorry about that.


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## paulm12 (May 22, 2015)

2 stroke engines almost always exhaust some unburnt fuel, due to the nature of the engine. "Each time a new charge of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port. That's why you see a sheen of oil around any two-stroke boat motor. "

My 2 stroke snowblowers have similar appearance around and below the muffler. You may also have excess oil in your particular mixture. as the others have stated.


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## tomlct1 (Jan 6, 2016)

That is MTD, not Murray, 4.5 HP, and I had what I think is identical to it last autumn. It was my father's, and I replaced some worn parts (paddles, cable, etc) and gave it to my son-in-law, as a spare machine. I mention this, because I THINK that one calls for a 40:1 ratio, not 50:1. As I remember, the front panel has writing on it, near to where the starter handle comes through, and the mixture was printed there, so if it is still legible, you could check there. Or if the cap is original, the original cap might have also had this info. Something to check & keep in mind, when you calculate how much oil it will need.


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## malisha1 (Nov 16, 2018)

Mine is 50:1.


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