2slow,

I do have to disagree ever so slightly with you

I have had multiple OS46AX's in several different planes and they all responded to power up and power down instantly. I currently have an OS108 in my now wrecked Showtime and once I leaned both the low end and high end it spools right down as does my OS160.

The only time I have seen an OS take a while to spool down is it's either really rich on the high end and it needs to burn off the fuel coming back to idle and if the low end it really lean. Just the opposite can also cause this. Lean high end coming into a rich low end, which I am pretty sure is his problem

Also, if he is running an 11X7 prop it's likely he is overrevving it. I know guys that fly that prop on a 46AX and it turns 10,000.

In either case, two or four stroke, he needs to get the engine tuned correctly. It's obviously lean on the high end since it want to shut off on the other side of a loop.


If it's a 61FX 2 stroke OS lists the props as

11x8-10,
12x7-11,
12.5x6-7

On a 4*60, I would be using a 13X6 with an OS61FX

Once he comes back to tell us about the markings on the engine, then we will know for sure and can steer him in the right direction