Take an old spark plug, knock the center out of it so you just have the metal part - cut the gnd. tip off. Then tap it for a suitable size length of grade 8 ready rod. Thread the rod out about 1" past the lower end of the plug metal threads and lock it using a nut.
Grind the threads off of the end of the rod about 1/4" from the end, that will go into the cylinder.
remove ALL the spark plugs
rotate the engine until #1 piston is down the hole - check with a screw driver.
put the tool in #1
SLOWLY rotate the crank using a ratchet and socket (DON"T USE THE STARTER !!!) clockwise until the piston stop. Make a mark on the balancer.
SLOWLY rotate the crank using a ratchet and socket (DON"T USE THE STARTER !!!) counter-clockwise until the piston stops.
Make a mark.
REMOVE the tool - TDC is 1/2 way between the 2 marks.
If the engine rotates without contacting the rod - extend the rod further into the cylinder another 1/2"
Last edited by efi-diy; 08/17/18 09:24 PM.
