# Gas Leak on My JD 316, Kohler



## Go-Green (Apr 25, 2013)

I have gas spitting out the crankcase vent tube. Any ideas how this might happen and what might be causing it?


----------



## Hoodoo Valley (Nov 14, 2006)

How's it running? My first guess would be a stuck float. Is that Kohler original?


----------



## Go-Green (Apr 25, 2013)

Tractor beam...

It's running good and it is the original Kohler engine. A new needle and float was installed and was checked for leakage. Also, the oil was checked to see if any gas got into the oil and there was no sign of gas in the oil. Puzzled how gas could get into the crankcase vent tube.


----------



## Hoodoo Valley (Nov 14, 2006)

My next guess was going to be the fuel pump, if it's a mechanical type, but if you aren't getting fuel in your oil, then it's not that. Is it possible that it just looks like it's coming out the vent, and actually running down the vent from a point not visible? Don't laugh! I had a friend who swore he had oil spewing out of his front differential while his truck was idling. Turned the engine off, and it would stop. I came over, and discovered that it was his oil filter that he never tightened on his recent oil change. I still give him hell about that one!


----------



## Go-Green (Apr 25, 2013)

Oh no, I'm not laughing. I'm open to any ideas. It's definitely coming out of the vent tube. You can see it spitting out the tube when you take off the air filter and you can see the inside of the tube is wet with gas. To give a little history, I bought this tractor last Nov. and it sat in my son's pole barn for the winter. I handed it over to a local tractor mechanic to give a good go-over to make sure everything was working properly. He ran new gas lines, new throttle assembly, adjusted gables, new needle and float, etc. You get the picture. He returned it to me and within a few minutes of running, I noticed gas dripping from the air filter cover. When I removed the cover, I could see the gas was coming from the vent tube located just below the carburetor. The mechanic came over and confirmed what I was seeing and he is as stumped as I am about what might be causing this.


----------



## Hoodoo Valley (Nov 14, 2006)

Go-Green said:


> Oh no, I'm not laughing. I'm open to any ideas. It's definitely coming out of the vent tube. You can see it spitting out the tube when you take off the air filter and you can see the inside of the tube is wet with gas. To give a little history, I bought this tractor last Nov. and it sat in my son's pole barn for the winter. I handed it over to a local tractor mechanic to give a good go-over to make sure everything was working properly. He ran new gas lines, new throttle assembly, adjusted gables, new needle and float, etc. You get the picture. He returned it to me and within a few minutes of running, I noticed gas dripping from the air filter cover. When I removed the cover, I could see the gas was coming from the vent tube located just below the carburetor. The mechanic came over and confirmed what I was seeing and he is as stumped as I am about what might be causing this.


Where's Robert Stack when you need him huh?:lmao:


----------



## Go-Green (Apr 25, 2013)

My mechanic called me last night and he has some master mechanic who specializes in tractors give it a look. I'm taking the 316 over to them this morning. I'll make a post as an FYI when I find out what the experts say.

Tractor beam, thank you for the comments. It helps...


----------



## Hoodoo Valley (Nov 14, 2006)

Go-Green said:


> My mechanic called me last night and he has some master mechanic who specializes in tractors give it a look. I'm taking the 316 over to them this morning. I'll make a post as an FYI when I find out what the experts say.
> 
> Tractor beam, thank you for the comments. It helps...


Is Robert Stack in to tractors now? :lmao: I sure hope they can figure it out. When you have a line, probably rubber...? that goes between the carb and the crankcase, you'd sure think there was a crack in the line at the point where the fuel is entering, but we'll have to wait and see. I know I'm biting my nails!


----------



## Mickey (Aug 14, 2010)

First thought that came to mind was FUEL PUMP. If the pump used with the Kohlers are anything like the pump used on the JD 318 with the Onan, these pumps use changing crankcase pressure to pump the fuel. Small hole in the pump diaphragm and fuel can get into the crankcase air passages.

I'd check that first.


----------



## Hoodoo Valley (Nov 14, 2006)

Mickey said:


> First thought that came to mind was FUEL PUMP. If the pump used with the Kohlers are anything like the pump used on the JD 318 with the Onan, these pumps use changing crankcase pressure to pump the fuel. Small hole in the pump diaphragm and fuel can get into the crankcase air passages.
> 
> I'd check that first.


But he has no fuel in the oil, and if he had a hole in the diaphram, then the fuel would be going in his oil, and that's the part that really puzzles me.


----------



## Go-Green (Apr 25, 2013)

Mickey said:


> First thought that came to mind was FUEL PUMP. If the pump used with the Kohlers are anything like the pump used on the JD 318 with the Onan, these pumps use changing crankcase pressure to pump the fuel. Small hole in the pump diaphragm and fuel can get into the crankcase air passages.
> 
> I'd check that first.


Thank you...I'll pass this infor on to my mechanic. Every possibility is worth exploring.


----------



## Mickey (Aug 14, 2010)

tractor beam said:


> But he has no fuel in the oil, and if he had a hole in the diaphram, then the fuel would be going in his oil, and that's the part that really puzzles me.


I'm not familiar with these Kohler engines so I'm shooting in the dark. If vent and pressure port are top side between the cyl banks like the valve spring covers and are close together then it may be possible. May be that any gas ingested may be being blown out the vent tube before it get a chance to get down to the crankcase.


----------



## Hoodoo Valley (Nov 14, 2006)

Mickey said:


> I'm not familiar with these Kohler engines so I'm shooting in the dark. If vent and pressure port are top side between the cyl banks like the valve spring covers and are close together then it may be possible. May be that any gas ingested may be being blown out the vent tube before it get a chance to get down to the crankcase.


I too, am not familiar with the Kohlers. My 316s Onan had the fuel pump right on the side of the crankcase and the PCV valve was right on top of the crankcase and went up into the air cleaner. Like I was thinking, there must be a crack in the hose and fuel is running down and entering through such a crack and being blown up into his air cleaner, but heck, who knows. No doubt about it, I'm certainly intrigued on this one.


----------



## Go-Green (Apr 25, 2013)

I will keep you all posted as I gather infor. I expect to hear something soon. If it's bad news, the JD X510, X530, X320, or X360 are looking really good right now.


----------



## JALaswellSr (Aug 21, 2011)

*Gas Leak on Kohler 316*

It appears that the change in gasoline in the past 10 or so years has caused a major problem with small engines (All Brands) especially those that have gravity flow tanks. According to a Tech rep at Kohler it is so sever that at times it requires a Cotton Swab (Like you clean your ears with) with valve grinding compound on it to clean the seat where the float bowl valve seats. This fills the crankcase with gasoline if the intake valve is open. Be Sure to drain and change your oil. Put a Gas shut off valve in the fuel line leading to the engine. Be sure to use it. I have had this problem with 2 Briggs and Stratton engines 5 HP on JD walk behind and 8 HP DR All Terrain Mower. My neighbor on his 16 HP Kohler Cub Cadet riding Mower. My 23 HP Kohler Command Pro in my JD 317 which is fuel pump driven does not have the problem. Put in a FUEL SHUTOFF VALVE.


----------



## Go-Green (Apr 25, 2013)

JALaswellSR...Put in a FUEL SHUTOFF VALVE.

The mechanic working on the tractor installed all new gas lines and a fuel shut-off valve. Should I close this valve and run the the line dry after each use?


----------



## Hoodoo Valley (Nov 14, 2006)

It all depends on the length of time in between uses, but I myself, always hit the fuel shut off valve on my gas equipment and run it out. In fact Honda contacted us via mail and informed us that the fuel in our generator should be swapped out every 30 days.


----------

