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oil in carburetor


cmenser's Avatar
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10-23-03, 08:50 AM   #1  
cmenser
oil in carburetor

I am noticing oil in my carburetor. This is a 20hp Kohler engine on a Crafstman rider. The engine dies after about an hour and I finally took off the air filter and noticed oil in there.
Any thoughts?

 
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10-23-03, 09:54 AM   #2  
Hi there!

Did you ever tip over this mower to get under the blade housing? If you did and it was tilted toward the direction of the carb to long, oil could have run into the carb. Anyway, I can tell you how to correct this but it does not mean it will not do it again depending on what your answer is for my above question. The first thing you need to do is take your carburetor off of the engine, and open it up and clean every nook and cranny including jets float needle valve seat. Every thing on there really well. To get it clean well use gumout spray along with a soft tiny clean brush or clean cloth/rag. After cleaning everything really well, install the carb back onto the engine. Do not start the engine yet. Remove the air filter and replace it. Most likely you have oil in it. After doing that it would also be a good idea to replace the sparkplug. After doing that drain all of the oil out of the engine, it is probably contaminated with gas. After doing that replace with the recommended oil for your engine. Usually it is "SAE 30"

After doing all of that, then you can start the engine and it should run like a charm. After you are done with all of this let us know how it goes!


Last edited by Terminator20; 10-23-03 at 10:22 AM.
 
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10-24-03, 12:47 AM   #3  
Hello cemenser!

Does the engine have spark at the plugs after it dies? Does it start right back up? Does choking the engine keep it from dying so quick? How much oil is in the carb? Is it smoking?

Sorry about all the questions, but it could be several things, and the answers to these questions will help determine the cause.


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10-28-03, 08:15 AM   #4  
cmenser
Cheese,
I have just gotten this mower, so I don't have a lot of history on it. I can tell you that when it stops running, that it does not start right back up. If you clean the oil out, just a little, and let it sit for a little while, it will start back up.
It has been bad enough to where the air filter was replaced about 6 times this season.
I did notice this weekend, after cleaning the engine up a little, that there is a leak in the left side cylinder gasket. I don't know if this is part of the oil in the carburetor problem or a seperate issue.
Thanks.

 
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10-28-03, 04:12 PM   #5  
Fisher
That is most likely the problem.
Fish

 
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10-28-03, 10:03 PM   #6  
I agree...I think you found your problem. The oil you see leaking outside the engine is not what is getting in the carb, but it is an indication that you have a leaking head gasket. Since this engine is overhead valve, a leaking/blown head gasket will blow compression gasses into the engine crankcase. These gasses have to vent out of the engine. The crankcase vent goes to the carburetor air filter housing. That's how the oil would get in there.


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10-29-03, 01:01 PM   #7  
cmenser
Cheese,
Is there a way to determine if it is in fact the head gasket and not a cylinder ring or a problem with the cylinder or valve seats without taking the valve cover and head off?
Thanks for the help.

 
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10-29-03, 04:44 PM   #8  
Fisher
The leaking cylinder head gasket pressurizes the crankcase,
forcing the oil in the breather. Common....
Fish

 
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10-29-03, 11:33 PM   #9  
There's no real way to be certain without taking the head off.


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10-30-03, 07:57 AM   #10  
cmenser
I am a little confused/ To start, this Kohler is a valve in block engine, not an overhead valve system. Also, because of this, when I look at the drawings, I am not sure how the leaking head gasket can pressurize the crankshaft area.
The head gasket is allowing air into and out of the combustion area. So I would think the only problem that this causes would be a problem with the fuel to air mixture in the combustion area.
I would not think the crankshaft area would get pressurized because of this.
Can you provide me with some more detail on how this would happen?
Thanks for the help.

 
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10-30-03, 04:33 PM   #11  
Ok, if this is a L head engine, and not OHV, then you are correct. Head gaskets will not cause this problem on a valve-in-block engine. I assumed that it was a 20 horse command engine, but apparently it is a magnum. (there were no model#s furnished for us to go by). The command is the popular kohler lately so it was easy to assume....I should have asked for model#s.

In this engine, rings would be the main culprit for oil in the air filter. It could also be a problem with the crankcase breather or a pinched or restricted breather hose. Normally Kohlers don't have trouble with their breather systems, but it's always possible.


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10-30-03, 05:36 PM   #12  
Fisher
Just for fun, post all of your engine's model numbers, so we can
discuss this coherently.
Fish
Just call me old fashioned.

 
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10-31-03, 07:56 AM   #13  
cmenser
Cheese,
I did open up the breather last night and found that it is not the same as the breather that is shown in the manual that I have. The breather that I have has a metal flapper over the ven hole where the one in the manual is some type of cylindrical shaped seal. The hose line is fine, no kinks or blockages.
I am going to pull the head and check the cylinders and rings, but I would assume that if this is the problem, it now changes from a Do It Yourself project to probably a give it to a mechanic to fix?
Thanks for the help.

 
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10-31-03, 04:58 PM   #14  
Fisher
Or you could just post your engine's model/spec numbers so
we know what you have, and save a whole lot of trouble!...

 
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11-02-03, 01:49 PM   #15  
needles
If the rings are bad,then you wouldn't need to give it to a mechanic. Just take the rings off,replace them,get a ring compressor,and just put it back in.

 
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11-02-03, 03:33 PM   #16  
Fisher
Or we could see the engine's model and spec. numbers so
we know what we are talking about. But I digress....

 
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11-02-03, 09:20 PM   #17  
Little more to it than that, like honing the cylinder and replacing head gaskets, and whatever else, depending on what engine it is.


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11-03-03, 09:52 AM   #18  
cmenser
I can tell you that it is a 20HP twin Cylinder Kohler Magnum.
The mower was purchased in 1995 which can date the engine.
I don't have any additional specs on the engine right now.

 
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11-04-03, 12:54 AM   #19  
The rings are probably the reason it is smoking. You could check the reed valve (metal flap you mentioned) to make sure it is closing properly, but that is a very uncommon occurrence. If you have some mechanical ability, a repair manual, and some common tools and a torque wrench, you can do this yourself. Pull the heads and look at the cylinder walls. Check for scars and scratches, check for a ridge around the top of the cylinder. You can see the top piston ring by looking between the piston and the cylinder wall. You can get a pretty good idea of the condition of the rings by looking at the end gap of the top ring. If it looks like it could be .030" or more, they need replacing. Not sure off the top of my head what the ring gap limit is on this engine, but your manual should tell you.


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11-04-03, 01:04 PM   #20  
Joe_F
Since it's a Sears, you can post the model # of the machine that's found on the tag (usually under the seat).

Then you can go to www.sears.com (click parts on the left) and it should give you what model # engine is used on this machine. You can enter the model # of the machine (probably starts with 502 or 917, which is a Murray made machine or an AYP made machine respectively). Browse through the parts list and post all the model #s you find there.

1995 era tells us really nothing as Sears machines come from a variety of sources.

Post all of that, and as Fish said, we can talk intelligently and not piss in the wind because we assume it's something else when it's not.

I agree with Fish.

 
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11-05-03, 01:33 AM   #21  
20 hp kohler magnum pretty much tells us all we need to know. It is an AYP mower. The spec# won't really tell us anything pertaining to why it is getting oil in the carb.


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11-06-03, 05:09 PM   #22  
Fisher
Wow, where is my last post?
At least we all now know what engine we are talking about,
took only a week and a half.
Fish

 
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