Top Dead Center TDC or Timing Pointer Verification

[soundguy]

In continuation of this thread...
http://www.bbcboards.net...69839

Here is a picture of the piston stop tool for my motor. P/N 342679



By following the instructions in the Evinrude service manual, that tool will not fit in the cylinder. The plastic dowell is too long. I'm guessing it must be cut to a certain length, but how does one know the length it must be?

And, why is the end of the tool plastic? If I "hold the flywheel firmly against the tool" like the manual says, it is going to bend the tool and the mark is going to be off a few degrees.

So, question 1. How do I calibrate the piston stop tool?
question 2. Is the end of the tool supposed to be plastic?

This may be more advanced troubleshooting than I'm supposed to undertake, but it is either this or a lawsuit, and I really want to avoid the latter. So I greatly appreciate any help.

[DoferGofer]

Good morning soundguy,

I am not a grue, just an old fart. Looking at your so call piston stop tool. Actually it does not mechanically stop the piston as the piston advance to TDC but, allows the tech to watch the plastic probe being pushed by the piston upward until the piston reach TDC.

[soundguy]

.

[RUSTY63]

There is a set screw on the side, loosen it and slide the plastic (yes it is supposed to be plastic) all the way into the tool.

Rotate the crank shaft with the spark plugs out (by hand) until the TDC mark lines up with the pointer then go past it about one half turn, install the tool, rotate the crank shaft until the piston touches the tool, follow the procedure in the manual.

The plastic will be dented or crushed if you pull against it to hard, that's why it comes with replacement ends.

[soundguy]

Thanks for the calrification Rusty.
The manual says to go only 1.5" past the TDC cast mark. Going 1/2 turn past TDC like you said is the ticket.

It was only off by 1 degree BTDC.