Briggs & Stratton engine piston

[rocky4]

Has anyone ever ran in to two riding mowers, with the same model and type having different pistons and rods in them?
Like, one being thicker on top and in height and the rod sleeve is further down from the piston top than the other piston.

 

[BlazNT]

All I can really tell you is the model of the tractor can have nothing to do with the engine. Engine model number is the important issue with this type of thing.

 

[rocky4]

Yes I know but what I have is two mowers with the same engine numbers. The only difference is the code which is 5 months different. The pistons will interchange ok but are not the same size other than diameter. Here is what happened.
On one mower, the rod broke and busted the housing. I don't know what happened to the rod as I could only find the top piece on the piston and some of the pieces on the crankshaft, so I don't know the length of that rod. I have another engine block which is good but the piston burned a hole in the top. The rod is good on this engine, so I wanted to take the piston from first engine and install it in the second engine, but since the pistons are different, by height, the rod from second engine is to long.
I looked up parts for the engines and only found one rod and piston for that model.
Does anyone know what the markings are for on the rod. There is a 28-31 on one rod.Does this indicate the length?
I tried to find a blueprint with measurements but have not found any. I have determined there is about 1/4 inch different in length.
Thanks

 

[BlazNT]

OK this is what I am asking you to give me. On the engine not the mower is an id tag with the engine model number. The engines could have been replaced in either mower at any time. It could have even been replaced under warranty. This is why I ask for the engine model number not the mower model number. I am betting they are the same HP but not the same engine.

 

[rocky4]

Here is the model from both mowers from cover on motor. The valve cover does not have anything on them.
No 1:
Model: 313707
Type: 0126-E1
Code: 020418ZE
No 2:
Model: 313707
Type: 0126-E1
Code: 010917ZE
I will attach pictures of both engines and pistons.
I could just buy another engine but this is a challenge and its a second mower. If you look at the engine crankcase, you will see they are different but both pistons will fit in both engines as far as diameter size goes.
Thanks for replying

 

[BlazNT]

Those are not interchangeable. Looks like they really changed them during a cost savings change over. Not a bad thing except for you. No interchangeable parts.