how do i know when the piston is at the bottom of the bore?

[dizzyrcdave]

how do i know when the piston is at the bottom of the bore ??????? as I'm on wearing in period and i need to let engine cool when piston at bottom of stroke:\

 

[sweetdiesel]

Remove your header pipe and look into the exhaust port. Turn the flywheel until the piston reaches the bottom of it's stroke (BDC). Now mark your flywheel with a sharpie or nail polish at the 12 o'clock position. Now you will always know where BDC is.

 

[MotoGod]

You can also just yank your glow plug and use a flashlight. When the piston stops moving down...that's BDC ;-) Liek sweet said above...use a Sharpie on your flywheel to mark where BDC is. If you use a bump box, make sure to mark the flat part of the Flywheel and not just the outer edge since it will get worn out from bump starting it.

 

[robmob]

You can do it by feel.

Rotate the flywheel in one direction until you feel some resistance. Now rotate it the other way until you feel resistance. You should then be able to tell where BDC is by doing this a few times and then mark your flywheel.

There you go. You now have all 3 methods of accomplishing the same thing.