Dear All, I need to time a small engine to 7/16" before TDC. I seem to recall reading somewhere on how this can be done via the spark plug hole with some basic measuring equipment. I have a vernier, dail gauge etc. Can anyone advise me please. I remember you simply stuck something down the hole them altered it by 7/16" and then adjusted the points to open. Regards, Ian.
Timing an Engine
Oct 07, 2004
1 Replies
Provided sparking plug hole is suitably placed (ie parallel to bore and over piston). It is simply a matter of setting to TDC, measure from plug hole edge down to piston crown with depth gauge tail on the verineers, open up verineers by another 7/16" and rotate engine backwards until piston again just touches depth gauge tail. Time mag or whatever to fire at this point.
If this is something you are going to be doing fairly often, a convenient tool can be made from an old sparking plug with a loose fitting rod up the middle (my father has one to suit Scott motorcycle engines).
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