tuning the zenoah engine (not noob stuff)

[decky]

having raced motocross for a while a few years back and usually having a slightly more 'rich' engine to make more power as it was tuned,i am getting confused with my zenoah and having issues deciding which is the best state of tune for it, ok here is what i mean, i ran it in my FG MONSTER for two tanks then started to lean it out for max power,i knew i was too lean when the carb bubble was getting empth now and then,so i went slightly richer with it,but now i feel i am loosing some power as i may be too rich,i am more used to a 'tuned' stroker,this is a standard zenoah 26cc,so where is that sweet spot? and how to i know i'm at the best with it apart from plug colour?

i started out H- 1/3/4
L- 1/1/2

 

[voo2doo]

As you know mate all engines are different.Go to factory setting and its all a case of 'ear' work from then on.
J

 

[Mike1970]

You're not looking for 1/4 or even 1/8th turns, more like "5 seconds" on a clock face.