L118 running problem

Johndeere3720 · Apr 25, 2010

Today, I was busy working on my tractor so i had my step dad mow the lawn on my L118. The battery has been dead lately because I didnt start my L118 all fall and winter. He was just finishing mowing and it started to run where it would be fine then loose power. It only runs at full throttle now and runs rough. All my filters are in good shape as they are all new. Im thinking that since the battery is dead, the L118 cant pump fuel making it run rough. The mower also has a full tank of fuel in it. It isnt beat up at all and has never really had any problems before except wore out steering parts which were replaced.

Johndeere3720 · Apr 25, 2010

:anyone: ?

Engine_Tech · Apr 26, 2010

The fuel pump is vacuum operated, so the battery is not involved with that. The ignition is made up of magneto coils, and they are not battery driven either.

Since you stated that you didn't run the tractor all fall or winter, it's very possible your carb is gummed up due to stale fuel. If you don't mix fuel stabilizer with your fuel these days, it will go bad in @ 30-days. Sitting all winter is plenty long to have issues.

I expect that some of the passages in the carb are plugged. You may be able to drain the tank (siphon out) and put some new fuel in. Mix in some Seafoam fuel system cleaner at 1oz/gal. It might clean the carb out if you go mow with it some more. If not, the carb will need to be pulled and cleaned.

Johndeere3720 · Apr 27, 2010

Ive already run 2 full tanks of fuel through it this season and mow once a week. It ran fine then.

Johndeere3720 · Apr 29, 2010

well, i talked to my grandpa about it today and i think it may be a bad alternator. I am gonna jump the mower with my tractor and see if it runs fine. If it does and sputters when I unhook the jumpers, I will replace the alternator.

Johndeere3720 · May 1, 2010

I found today what the problem was with my L118. I started by hooking the jumper cables from my Yanmar to the Deere. The Deere started up but still ran rough. So I unhooked the fuel filter to see if the Deere was starving itself for fuel. Doing this made fuel fall backwards out of the fuel pump. I took a cup, filled it with gasoline and put the little hose from the fuel pump into the cup. It still wasnt running perfectly so i tapped the fuel pump with the pliers. Then the Deere ran fine! I hooked the fuel filter back up to it and it runs fine again! :thumbsup: I did a test run by mowing a small area and idling the engine. Now that it runs fine, and I am happy with it. Now I can mow the lawn again.:thumbsup: So it it ever happens again, i atleast know it is my fuel pump.