JD L120 Engine Problems

[jinman]

. . . One odd thing. The manual says the parking brake has to be on and the brake pedal depressed for the machine to start. He has never had to engage either one to get the machine to start before. Is the manual wrong or perhaps the design has changed?

My LA145 requires the brake to be depressed to start, but it is my choice on whether I engage the parking brake lever or not. If I engage the lever, I can remove my foot from the brake pedal. I suspect your friend's brake pedal safety switch has been out of adjustment, internally bad, or jumpered around (in that order with jumpered being a very slim possibility). Safety switches are notorious for going bad and his may have been bad for a very long time. In an unrelated, but similar switch story. I used to be able to start my Kawasaki Mule in gear even when the manual said it had to be in neutral. After about 350 hours of use, it finally started to work that way. You just never know. . .

 

[bz1]

OK, I brought the machine to my house with the intent of figuring this out and fixing it. First thing I checked was fuel and there was no fuel going into carburator. I pulled the plugs, good spark, then my was to perhaps squirt a little gas into cylinders and seeing if it would fire. I checked to see if pistons were moving when turning the engine over by hand - nope, neither piston moved. Bad sign. Removed the engine and opened it up. Both connecting rods were trashed and a big chunk broken out of cylinder wall. Bad problem, basically trashed engine. The guy says it just quit, no noise or nothing. I really didn't expect this to be so bad. I suspect the problem was low oil even though he swears it was OK. I only drained about a cup of oil from engine before I opened it up. There should be more than that right? The big end bearing surfaces on the rod were pretty scored up. Oh well, new engine time. Anyone have any comments on what to replace this with? Same engine model or something else? Thanks.

 

[Markcuda]

Anyone have any comments on what to replace this with?

A owner that will keep the proper amount of oil in it.:laughing:

 

[Kyle_in_Tex]

5 years old with only 80 hours....hummmm...I'd be looking for rat's nest or mud daubers nests blocking the cooling fins under the top cover.

Oh, and also an owner to put oil in it.

If you go into a lawnmower shop, the synthetic Briggs Oil (I think still) offers to double the warranty if you use their synthetic oil.

 

[jinman]

I think I'd measure the bolt pattern and output shaft diameter to be sure my replacement was the same. I don't think I'd go back with the original engine. If you can find one with a low oil shutoff feature, that would be good. There are lots of places on the internet selling engines.

It appears the shop owner's comment in the original post may have been closer to correct that I thought.

 

[tomnky]

try this link:John Deere L120 Outdoor Power Equipment Repower from Small Engine Warehouse

 

[bz1]

Thanks Tomnky, that web site has good info.

 

[tomnky]

You are most welcome!
I thought the dimensions would help save a lot of time.