Originally Posted by JimN
Why not use a signal generator and vary the frequency so it can be watched, to avoid advancing too far? Plenty of free programs are available and some can be varied in 1Hz increments.
Absolutely!! If you have a sig gen available that would be super easy. I don't have a sig gen but I did have all the components to make one. Frequency only maters in that it must be greater than the equivalent of 400ish rpm. A faster rpm does not advance the hr meter faster but the tach/meter must believe the engine is running ... so, idle or above. S