Presents
Johnson TD/TN Repair This page is
designed for educational purposes only.
POWERHEAD SERVICE
disassembly and reassembly of the powehead takes about an hour. We start by removing the 4 screws and 6 nuts that hold the back of the block in place. Here we see the back of the crankshaft and piston connecting rods. The correct location of the connecting rod backs is shown above. close up of part number location on piston connecting rod. Make sure to note the proper location of the tops of the pistons before removing them from the block. The piston is placed the same way in the TD and TN models. Piston removal is easy, push slightly on the back of the rod and pull out from the top of the block. note the nasty corrosion in the water passage on this TD-20 Inside of the cylinder head inside the engine block indicates this block is in very useable condition and not in need of boring, etc. Here we see two pistons and the crank which are all in very useable condition. Replacement in reverse order. compressing the rings on these motors is easily done by hand, just make sure the rings are aligned properly. .
