Timing Question

[MikeL]

My '76 R75/6 is fresh off a cylinder re-bore (first over), seems to be running pretty well, and I'm trying to get it completely tuned. Checked my timing today- at idle (800-1000rpm) the "S" was not visible. Increased RPM and "F" came into window and traveled to the very top of window at full advance. The machined "dot" above the "F" was hardly visible at full advance (too high). From what I've read, my timing would appear to be too far advanced, but I've had no noticeable pinging, and it seems to be running well, though I have no similar bike or Airhead experience to compare. Note: a PO/shop installed a Dyna III ignition on the bike.

Thoughts? Thanks!

[Garnet]

The dot at the very top of the window is about 5 deg too far advanced. 2 to 3 degrees of extra advance is usually considered max. Many factors come into play. A powerful spark will allow more advance, as will high octane fuel and or lower compression. Also a slower rate of advance (not reaching max till 4 or 5000 rpm) will also allow more advance.

It wouldn't hurt to get a degree wheel and check the accuracy of the flywheel marks.

Also look at your plugs with a magnifying glass to see if there are any signs of detonation.

[Duane Ausherman]

An engine wants to be advanced just under the point where it pings. The stock settings are just a beginning point and not the optimum. If you are sure that you aren't getting any pinging (pinking in some outback places) then be happy.

Besides, the F mark is far more important than the S mark, but I always want to know why the unusual spread.