Positive Stop Tool

[Anonymous]

Somebody help me here. I don't see how a dial indicator isn't accurate.

If I check the piston at say .200 before tdc and get say 20 deg. Then I spin the motor back and at .200 after tdc I get 20 deg. I would say I've found true TDC. I started out using the positive stop on an old kaw I had, but hit the valves. After that I went to the dial indicator and never thought it wasn't accurate.

This is the best way to do it. You cannot find TDC accurately using a dial indicator unless you make measurements on either side of TDC - just like you would with a positive stop.

I use the dial indicator and not a positive stop. There are 2 reasons:

1) I don't like to take a chance gouging my postons using a positive stop.

2) The dial indicator is needed to degree in the cams - so if you have one USE IT.

[mike J]

A dial indicator is just as accurate as any method if you use it correctly. Turn piston to indicator stops moving. Then zero indicator. Back crank off say .05" and read the degrees then turn foward to .05 and read degrees. Move your pointer untill the before and after degrees reads exactly the same. That is the only way to do, if you just zero your indicator when it stops moving you can be off 3-4 degrees. Mike J