I have read through the various posts on this site about tuning YS engines. I have a brand new YS63S. I am running some left over helicopter 15% power master fuel with a 11X8 APC prop. I am using an OS F-type plug. I have a couple of questions:

1) All the references to needle settings are begin with the high at 2 turns from closed and adjust and then the low at 1 to 1.5 turns from closed and adjust. For the low end, is this number in reference to fully screwed in (ie. fully rich)?

2) I set the high end (1.90 turns from closed). However, as I was trying to set my low end, I noticed the high end began to have problems where the engine cuts out at the high end (3/4 throttle). It didn't sound like it leaned out but I richened it. This only made it quit earlier. I am advancing the throttle slowly, so I am not sure what this could be. Is it too rich. The engine is new and only has about 3 tanks through it so I am cautious about leaning it out too much.

3) Finally, initially when I did have it running ok, (high end at approx. 11k rpm), when I would cut back the idle would come down to 2400 - 2600. I have read that it needs to be around 2000 for the air bleed system to really work. Is this true? If so, how do I adjust it? I tried the low end needle but this didn't seem to help.

Thank you so much for your help.

Happy new year!

Sincerely,

Jeff