Riding Mower Chokes and Dies

Country Lady · #1 04/22/14, 04:26 PM

We have a Sears riding mower with a Kohler engine that we purchased in 2003. It will choke down on most anything but air. We can run over a small pile of leaves or very sparse grass and it will choke down. We have to cut grass in 1st gear with our foot on the clutch and just move a few inches and stop till it catches up then move a few more inches. Now it has started sputtering like it is out of gas and dies. After it stops, it will start again and run for a few minutes more then sputter and die again. We have replaced the sparkplug, air filter, fuel filter, removed the gas tank and cleaned it and the line up to the fuel filter. We have used ethanol free gas for the last 3 years. Any suggestions on the next thing to try will be appreciated.

arabian knight · #2 04/22/14, 04:31 PM

Even though you have used ethanol free gas for the last three years it is 11 years old. And I guess ethanol gas was used in for the first 8 years?
In that I would be looking at the fuel pump.
I have had to replace the gaskets in mine twice so far as the gas with ethanol does 'eat up' those thin gaskets and diaphragms that are in the fuel pump. And even if it isn't gas related with the type of gas used, It still could be the fuel pump., repair kits are available to buy.

geo in mi · #3 04/22/14, 06:58 PM

I agree with the fuel pump. Also check the air line to it.

geo

Harry Chickpea · #4 04/23/14, 12:23 AM

Just a guess, but up on top, under the cowling, is the fan that blows air around the engine. Remove the cowling and look for mouse nests and clots of grass. They can cause overheating that will give the symptoms you describe.

Super55 · #5 04/23/14, 12:38 AM

From what you are describing it almost sounds like a hung up needle valve or partially clogged jet on the carb. It's pretty typical with equipment that sits for months such as mowers, powerwashers, tillers etc.

Should be an easy fix if your familiar with tearing down and cleaning up a carburetor. If not you can find a vid on youtube probably. The biggest issue is just making sure you have the rich/lean screw set correctly. A lot of these screws aren't adjustable anymore thanks to EPA standards but your tractor should be old enough that is can still be adjusted.

GunMonkeyIntl · #6 04/23/14, 06:25 AM

I second trying to clean the carburetor first. It is not as difficult as it is intimidating to the uninitiated - go slow and take pictures with your phone and you will have no problem getting it back together.

It may not have a fuel pump. Generally, if the tank is in the rear, it will have one, but if the tank is in the front, above the engine, it will be gravity feed - one less thing that can go wrong.

arabian knight · #7 04/23/14, 08:24 AM

Quote:

Originally Posted by GunMonkeyIntl

I second trying to clean the carburetor first. It is not as difficult as it is intimidating to the uninitiated - go slow and take pictures with your phone and you will have no problem getting it back together.

It may not have a fuel pump. Generally, if the tank is in the rear, it will have one, but if the tank is in the front, above the engine, it will be gravity feed - one less thing that can go wrong.

But even if it is upfront and gravity fed like my mower is they still may have a fuel pump with all sorts of very thin diaphragms in it. The bigger that engine is 16 horse 18 horse etc. the better chance that it does have some kind of pump even if the fuel tank is upfront.

ksfarmer · #8 04/23/14, 08:31 AM

Check or replace the fuel tank cap.

simi-steading · #9 04/23/14, 08:44 AM

You could also have an air leak...

With the engine running, take a can of WD-40 and spray around the intake mating surfaces between the carb and the engine block.. if you are sucking air, when you spray it, the engine will run faster or similar.. you will hear a difference..

If no air leak, then I'd clean the carb...

This doesn't sound like a fuel pump problem.. if it was, even without mowing, it will starve for fuel..

Also, check your belts and blade spindles.. if you have something that is not moving freeely it can put too much load on the engine, then once you hit the grass, it's way too much..

Nimrod · #10 04/23/14, 09:13 AM

I agree with those that said the carb needs to be cleaned. the engine acts like it is not getting enough gas. There are a bunch of small passages and a needle valve in a carb. One tiny piece of gunk will block a passage.

If you are not a do it your selfer you can take the carb to your local small engine place and they will clean it out for you and put in a few new parts.

You can buy a can of carb cleaner at the auto parts store. It comes in a gallon can, like a paint can, with a dip basket. Follow the directions. Most say to remove all the plastic and rubber parts before you submerge the carb body.

Take pictures as you take the carb apart. You Tube has some good videos on cleaning out a carb. There should be a manufacturer name and number on the carb. The manufacturer's web site may have an exploded view of your carb.

If your carb has high and low speed mixture screws, you will need to adjust them while the engine is running once you get it put back together. BEFORE YOU TAKE THE CARB APART, gently turn the mixture screws in (clockwise) while counting the revolutions, until they bottom out. Write the number of revolutions down. When you put the carb together again, gently bottom out the mixture screws and then back them out to the same position they were in before you took it apart. This should be close enough settings that the engine will start. Set the throttle so the engine runs at high rpms and adjust the high idle screw until the rpms are at the peak. Then open the screw (counterclockwise) a quarter turn to ensure you have a rich enough mixture that the engine won't be damaged. Use the same procedure on the low speed screw with the engine at idle.

I would at least replace the needle valve when you rebuild the carb. The small engine shop has carb rebuild kits with all the parts you need and a bunch you don't. They are pricey. The last one I bought was over $50. You can buy the parts separately. I now just buy the needle valve and what ever gaskets I need. Do bring the old parts in with you so you are sure you are getting the right parts.

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Country Lady · #11 04/23/14, 07:48 PM

DH worked on the carb and replaced the belt on the blades. The mower worked much better. Thanks for all your advice.