Colin

I'm a newbie to the YS170 (non cdi) but I can I see some similarities in our experiences. In my case I run 30% heli regular oil and 18.1X10 APC , 20oz tetra tank. Up to 25 flights I couldn't get much more than 8 1/2 minute flights the performance was no better than my OS160. Switched to 18.1x11 and started to lean the HS. At 50 flts I was at 1 1/4 turns HS and pump set flush getting 7600-7800 rpm but going thru glow plugs like crazy. I set the HS to 1 3/4 and got 7500 rpm and stopped killing glow plugs my fuel economy increased to 9 mins 40 sec. At 75 flts I went to a contest. When my engine wouldn't start during practice a number of experienced D6 pilots offered their assistance. They felt the engine was too lean and richened the HS to what ended up being 2 turns. We measured the rpm it was still 7500. This got me thru the contest but I suffererd greatly on the 1/2 square up w/2 of 4. No power at the top. From 75 flights to 100 flights the situatuion got worse but I had also developed a leak in the muffler o-ring. At 100 flights I changed the o-ring leaned the HS back to 1 1/4, ordered up some some nice hot Texas weather 95F I don't know what rpm I'm getting but the motor is now living up to my expectations. I can do the half square with little over 1/2 throttle. So far I've flown in 95F degree temps 3 days in a row and the glow plug is holding up. I plan to go out again today (99F) I probably won't even measure the rpm, it doesn't matter, what ever it is it is. The engine is running great oh yeah I'm getting 10 min 30 sec on the 20 oz tank.

Glen