piaton stop tool

i have a 175 evirude powerhed im using for replacement of bad 150. im useing
the fly wheel off my 150. its said that i need to set my timeing pointer due to casting changes amongst blocks how can i make a piston stop to set my timing pointer or is there another way if any one can help me with the setting of my pointer so i can static time my motor .
also my manual says to time it to decal on motor but it is no longer there
what should i time it at 1983 johnson powerhead 175 hp
and also ive seen some post that when you static time it you subtract 4 degrees .but have seen post that also said 2 gegrees less .
if anyone can give me the run down on the inital setup it would be good
thanks benny b

Re: piaton stop tool

benny, a bolt and a couple of nuts will work just fine. All you need is a feeler for TDC. Get a bolt that's a bit smaller than the spark plug hole put a couple of nuts up high on the bolt and tighten them together. The bolt should go through the hole and the nuts will shoulder up on the outside. Hold it firmly in place while turning the flywheel until it stops against the end of the bolt.

Re: piaton stop tool

wombat sounds good but will that give me exact top dead center or does it really just need to be really close ,still alittle confused ,when i find dead center
my o degree mark on my flywheel is what i need to move my pointer to ?
thanks bennyb

Re: piaton stop tool

Break the porcelain out of a spark plug and then tap the shell for a bolt. Screw tool into the plug hole. Rotate the engine by hand as you gradually screw the bolt in that you tapped the shell for. When the piston strikes the bolt but will just barely rotate past it you found TDC. At that point it doesn't matter where you mark anything. A mark on the flywheel and a mark on the block will indicate TDC when the marks line up. If you have a mark on the flywheel, mark the block. If you have a mark on the block, mark the flywheel.

Re: piaton stop tool

Rotate the TDC casting on the flywheel to a couple inches past the timing pointer.
Use your piston stop tool to mark the piston depth at that point and use a pencil to mark the edge of the flywheel at the pointer.
Rotate the flywheel until the piston contacts your piston stop tool. Mark the edge of the flywheel.
Draw a straight line between your two pencil marks. Mark the midpoint of the line on the edge of the flywheel.
Turn the flywheel until your mid-point mark lines up with the timing pointer.
Move the timing pointer to line up with the cast in TDC mark.