I recently purchased a pattern plane with a YS 91 for power & would like to pick up an owners manual, but even more importantly, I would like to hear from those that are actually running the engine. The REAL experts.

Thanks,

Ken

Ken,

I will try and scan a copy of mine for you. Is yours an AC or FZ. The FZ is a later version with a different carb housing. Use OS Type F or YS plug. 20/20 fuel is recommended. Do you know when was the last time the engine ran?

Azhar

slim56, note that the FZ is stamped AC on the crankcase...as azhar noted, you have to look at the carbs to know the difference. FYI, here's the FZ manual in PDF format:

http://www.yspower.co.jp/pdf/fz91-e.pdf

Thanks, snsmith the manual will be very helpful. Where on the crankcase is the "AC" stamped? Any other recommendations or helpful hints, that any of you have will be greatly appreciated.

Thanks slim

Left side, right above the mounting flange. It should be visible under most mounting conditions (cowl off, of course).