Miscellaneous Stuff

A Fox .35 Stunt engine dressed in McCoy colors. All photos by Gene Pape.

A Fox that never was

By Gene Pape
June 2026

Maybe because my first large engine was a McCoy .35 Redhead, I’ve always liked engines with shiny crankcases and red painted heads. I also have a soft spot for one of the most popular .35 engines of all time, the Fox Stunt 35, which is by comparison kind of an ugly duckling.

My collection of Fox Stunt .35s has grown over recent years because I can’t seem to pass them up when they are available really cheap (or in many instances free). Recently, one appeared on eBay with a red-painted head. The bidding started out cheap, so I bid on it just because. Someone else bought it, but the idea stuck. About a week later, this one came up on eBay. It was ugly and it was really cheap. I bought it for $13.29 including shipping. One of the best deals I have gotten since the price included a genuine Fox box.

As it came from eBay, before cleanup and repainting.

I cleaned it up and took it apart in preparation for making it beautiful. The first step was using acetone to remove most of the paint. With a bunch of scrubbing with the acetone and a brass wire brush, most of the paint and crud came off. Next came about a day of soaking in a crock pot with full strength antifreeze (diluting the antifreeze with water will horribly stain Fox crankcases). A bit of scrubbing now got everything clean enough to go into the tumbler for polishing. See my August 2020 column: Cleaning up an ugly engine.

All the old paint has been removed.

Everything was now ready to paint the head and do final assembly. That’s when I got really stupid. With these old Fox engines, it is common for the wrist pin to become solidly stuck in the connecting rod. My standard procedure for this is to simply reassemble the engine and run it. The fuel and vibration will release the stuck pin and everything is fine. Sometimes however, I decide to get fussy and free this up before reassembling the engine.

My procedure for this is to soak the piston and rod assembly in a crock pot with antifreeze for a rather long time until the pin starts to loosen up, then apply solvent and lube of some sort. I then heat everything with a heat gun and carefully tap on the wrist pin with a punch while securely supporting the piston. This time I forgot the carefully part of the process and knocked one side out of the piston.

Broken piston.

After calling myself all kinds of names I scrounged around and found a later used piston and cylinder assembly which is quite a bit heavier than the one in this engine so it would vibrate horribly had I assembled it with the original crankshaft. Fortunately, I also had a crankshaft with the proper counterweight for the later piston.

Finished!

With all of that taken care of, I could now assemble my McCoy Redhead .35-appearing Fox Stunt 35. I think it looks great. I may even try to run it one day. For now, it will have to just be happy sleeping in its box.

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This page was updated June 13, 2026