Daylight99

Hi friends
I have read posts about changing the timing on a Zenoah engine but the one thing I can not find is how its done. What is it that you move on the engine to effect the timing?

Bob Russell

OLD_SLOW and in the WAY

what is probably being refered to is the port timing not ignition. the zenoah red coil has an in tegral circuit board the advances the timing.
port timing is accomplished by removing material from the roof of the exhaust port and the intake timing is either done by shortening the intake side of the piston skirt or the floor of the intake port.
dont just start hackin away at it you can ruin an engine real quick

good all around timing numbers for a healthy 231/260 zenoah are

178deg exhaust
153deg intake

Daylight99

If your using a dremel or file to remove material how do you know when you have reached the timing numbers your after? Do you remove alot of material or a small amount?

OLD_SLOW and in the WAY

use this degree wheel it should print out about 7" diameter if it dont e mail me and i'll send ya one
or measure from the bottom of the cylinder skirt to the top of the exhaust port and take away material till it measures 1.605" this will get ya near 178 deg exhaust for the intake from the bottom of the ring land to the bottom of the piston skirt on the intake side take .030" off this will get you near 153deg intake timing

i'll get some pics of how the degree wheel set up is cuz i hate typing

p.s for porting i use a 90deg pneumatic die grinder at 40psi and carbide burrs