The Damage
Hmmm…this isn’t good. The lawnmower grenaded. It looks like the con-rods fused to the crankshaft, and then inertia took over. One rod broke into about 3 pieces, the other into about 60 smalll fragments. So, I ordered a couple new con-rods, and a crankshaft. I could possibly have had the crank machined…but, its only $250 and the machinist would cost $100, and it might not work. Plus, since the bearings are integral to the con-rod there are only three size options: standard, 0.010 over, and 0.025 over. What are the odds that he would be able to get that… Given my luck?
Dissaembly
Time to disassemble and clean it; first remove the carburetor linkage. Several pictures to make sure I get all the rods, and springs back to the right levers and holes.
Next the intake, the wire harness is strapped to the intake manifold. So, there are a couple connectors to remove in order separate the manifold from the block.
There’s also a connection for the fuel pump.
Finally, the cylinder heads. The heads are matched and marked….the pushrods and lifters need to go back into the same positions…so I marked each with a little bit of tape.
Cleaning
Lots of scrubbing and washing with towels, mineral spirits, toothbrushes. All shiny clean and ready for reassembly. Only problem? One of the wrist-pin springs launched into outer space as I was removing it. I was 500ms too late in getting my thumb over it to keep it from getting away. Dang it! I went back to the parts web site….$0.85 ea, $10 shipping! I bought 4!
All organized and ready ro go back together….as soon as the wrist pin clips arrive.
The Damage: Part 2
So, now that I have it clean, and disassembled I can properly inspect the damage. It’s a little worse that I’d first thought. As you can see both of the cylinder walls are cracked. It looks like the cracks are below BDC. I won’t know for sure until I put the crank back in. It is ONLY a lawnmower, right?
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