RE: Ryobi 4 stroker, whos flying them and what do ya think.
Mr. P.cub,
I ran my Nosen Champ(108"?) and Ryobi yesterday mounted upright. APC 18-8Wide, CH ignition, stock plastic barrel carb, bored out jet and got 5600 rpm. I then took the throttle barrel assy out and rotated it 180' and gained another 100 rpm to 5700. ???? That is with the timing at 30' btdc and idle at about 0'. Idle was as low as 1100 but liked 1300-1400 better. Just out of curiosity I turned the whole carb assy over so the pump bulb was on top and lost 1000 rpm then switched it back.
Flew very well but I didn't use locktite on the head/mount bolts and they came loose/out during flight and leaked oil everywhere and died on aproach. I cut a new gasked and locktited the bolts and mounted the engine inverted and turned the carb over so the throttle wheel was again on top. 8" breather tube running to top of firewall above oil pan. It ran OK, only 5300-5400 rpm and the idle was very surgy and would often die. Also, oil was occasionally spurting out of the breather checkvalve. This made a mess of the front of my plane. Tonight I will turn the engine back upright. It seems to be much happier.
Bud Nosen Aronca Champ, 108" span, boat load of wing area, 14#, 55' takeoff roll. With the engine back upright and the 5700 rpm, it should shorten the takeoff noticeably.
Doug