Fox 15 Slant Plug - How lean

Set it on the off-peak side of max, a couple of clicks toward rich. Only the earliest in the Fox 15 series has ever reportedly operated in a ("usable") 4-2-4. That was the so-called "steel fin" Fox 15, a slightly smaller looking engine than the 15X. Use an 8-4 prop with all of the baffle piston Fox 15's other than the "XXX," which wants a 7-4.

Personally, the smallest engines I have experience with running in a (usable, useful, whatever) breaking mode are 19's, and only a couple of those would, such as the 1957 model Fox, and the Testors RH engine. Someone at one or another of the internet message forums recently made a comment on getting a (the word "usable" is added again) breaking run from an 09/10, I think, but that sounded hard to believe to me!

K.

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As previously established, there's no magic whatsoever about breaking from 4-2 and back again. ANY 2-stroke engine will happily do this, just maybe not when or how much you want. If you listen to a poorly-set F2A motor, you will frequently hear it go from 4-2 as it goes upwind and downwind, at 35000 RPM.

I can't actually answer the question about the Fox 15 slant-plug, as most people just give up before they ever get it started. It's hard to throw, as well - tough to get a good grip on, and it's surface area:weight ratio is too high to carry well. It's like trying to throw a ping-pong ball.

In order to run a 15X, start it in one flip by using the type of procedure preferred by competition combat fliers, and easily stop collecting any nicks in any fingers, or having to carry Chicken Sticks. The procedure is thoroughly covered in several threads; it's called the Back Flip Start, and it works.

Only after enjoying the little engine's capabilities for several years will you want to send the by-then well-worn remnants to the far NW environs to enter by Proxy in the 15X chunking event.

In order to satisfy the Fox disparagers, spend a lot more money to obtain a new engine. Or ignore them, as I (usually will) do.

Kiwi