timing

[1project2many]

Originally Posted by yoshi

I can see the top of the piston through the spark plug hole with a torch

Yes, but how do you know it's at the peak of its travel? As much as ten degrees of error in the timing tab is difficult to catch when looking through the plug hole.

There are methods to determine very closely without special tools. To really do this correctly you need to make or buy a tool called a "piston stop." You could "eyeball" it if you can put a screwdriver or small rod on the piston through the plug hole. By turning the crankshaft manually, and slowly, with a wrench or ratchet and watching the rod for vertical movement, you might be able to confirm the timing mark is oriented correctly when the piston reaches TDC.