maukaonyx

Bax, I bought one of these engines used, but seems to be in like new condition. I got it started at the 3 open turns position for the high needle valve, but found that to be way off on peaking out the engine. I think I had her running near peak at about 1 1/4 turns open. Is this reasonable or am I way off? It just ran slow and rich at 3 turns and in until I got to about 1 1/2 when there was improvement. I still have to run it more and tach it. It seemed awful slow and I think that is due to too much prop. I read another of your threads and you said 15x6 is too much prop for this engine. I was starting with 15x8, haha, based on the manual recommended range, which I believed. Your thread set me straight, to go smaller and get the RPMs up around mid 9k. Your advice, as usual, is appreciated. Thanks. Jon

Bax

My Feedback: (11)

When the throttle is opened to full, and you have used a tachometer to set the high-speed needle valve so that it's just rich of peak RPM, you're ok. If the engine runs very nicely at that setting, then you have the "correct" one. The actual number of turns a needle is out is never a relevant number, unless it's changed from where it's tended to be over a long time. The change is what may cause concern. For a new engine, it is what it is.

The propellers recommended by O.S. are mainly for noise reduction. They have very strict noise regulations in most parts of Japan. If you get a prop that allows the engine to turn in the mid-9,000's on the ground, and flies the airplane well, then you have the "correct" propeller.

maukaonyx

Thanks Bax. You basically are saying my setting is ok, not unreasonable, it is what it is! I will go from here. Thanks again. Jon

maukaonyx

I used a 14x6 MAS today and sure enough got the rpms up to 10k. While I saw the tach hit 10,500, I was happy with the smoke and sound at 9,800 so that is where I left the needle. I had to open the low needle to about 2 3/4 turns from closed, the factory setting is 2, and I got a good transition from idle to top end. Idle was around 2,300. Since the club field is nice sod farm grass, that idle works fine. On tarmac, the plane would be rolling. Now the real test is in the air, with a maiden soon. Thanks Bax and others who asked many questions that also helped me. Jon