Not Model A- Kohler engine trouble

Quigley1930

Quigley1930

Senior Member
Have a 12HP Kohler engine on a Gravely walk behind tractor. Starts and runs very rough spiting raw gas out of choke orfice. Carb has been serviced. The tractor has been sitting for several years (5-6?). Would a poorly seating valve cause this. Any and all help will be appreciated.

Sewall
 
An intake valve that is hanging up can allow gas to spit out carb-also make sure carb. needle and seat is working properly-if not the carb will overflow and excess fuel can end up in combustion chamber or even in sump oil. Some Kohlers have a mechanical compression release that holds one valve open momentarily to ease pull starting
 
my first thought was stuck needle causing extreme rich condition. Is the plug wet with fuel? Hows the oil look/smell?
 
Try some Sea Foam mixed with fresh gas without ethanol. I only use good gas without the corn crap in all my old cars and small engines.
 
I think you are going to find the intake valve hanging up a bit.Where it still runs it will just be a little.A compression test will just be off by a couple of pounds,not enough to notice while testing.Most Kohler 12's were equipped with ACR,(automatic compression release)but when they fail they fail to release compression,not keep it released.I bought a tractor with a K341 in it,in the late 70's.The ACR had failed,and is still failed.It just cranks over a little hard when cold.It now has over 2000 hours on it and is just starting to use oil.All my Gravely experience has been with their own 7.6 engine,when they went to Kohler it was a huge upgrade in my opinion.
 
i would start with what Tom mentioned... run sea foam through it
i have done this numerous times and it helped free things up.. i have to mix it with corn crap as straight fuel is not available near me....
 
Ray64 said:
Is there any one brand of gas that does not contain ethanol?
Click to expand...

no, usually premium or midgrade does but you would have to check which stations do this.

honestly ive never had issues using ethonal gas as that's all we had for the last 25+ years in my area. I never do anything special either (most of it sits in the mowers all winter with whatever was left in it) start up just fine in the spring.

i notice the lawnmower shops are gouging people selling non ethonal gas in a half gallon can for $8.00...
 
Well I really want to thank everyone for your replies. I was only able to do a compression test today and it was right at 130PSI. I don't know what it should be but sure is better than my A:D I will do some more tinkering and let y'all know what happens.

I'll get some good gas tomorrow and Sea Foam and see if that helps.

Sewall
 
Quigley1930 said:
Well I really want to thank everyone for your replies. I was only able to do a compression test today and it was right at 130PSI. I don't know what it should be but sure is better than my A:D I will do some more tinkering and let y'all know what happens.

I'll get some good gas tomorrow and Sea Foam and see if that helps.

Sewall
Click to expand...

I know on my Kohler,.if the point are not set with a "mag buzzer" it will not
run! I put a new set of points in it and acted as you discribed in your first
post. Timing is VERY crittical on the Kohler !....so I used my mag buzzer..

Dudley
 
katy said:
What's a mag buzzer?
Click to expand...

It's an audibule tool that DOESN'T run current threw a magnetto. I also use it
on regular ignition systems, insteed of a test light..
 

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I used to have a Gravely. It was a beast that could chew through CT brush to expand our yard into a previously wooded areas. With a very large and DANGEROUS circular saw blade replacing the cutting deck we could trim stumps flush with the ground. A fun machine well worth fixing.
 

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Well, I got her done! Followed a lot of advice from y'all and locally and my Gravely is running good. I put a little oil in the spark plug hole and turned the engine over a few times. Then followed Tom's suggestion with good gas and Sea Foam. Installed a new bowl gasket. Don't know which worked the best (maybe all) but is now running good.

Thanks again for everyone for your help and ideas.

Sewall
 
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