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Engine basics => Engine set up tips => Topic started by: Brent Williams on February 25, 2016, 03:20:09 AM

Title: Fox .25 - What else fits this bolt spacing?
Post by: Brent Williams on February 25, 2016, 03:20:09 AM

Just curious what else fits the same bolt spacing as the Fox 25?  I much prefer the run of modern engines.
(http://i.ebayimg.com/00/s/NDEzWDUwMA==/z/AlsAAOxy7nNTVj5Y/$_35.JPG?set_id=2)

Title: Re: Fox .25 - What else fits this bolt spacing?
Post by: Brett Buck on February 25, 2016, 08:34:15 AM

Quote from: Brent Williams on February 25, 2016, 03:20:09 AM

Just curious what else fits the same bolt spacing as the Fox 25?  I much prefer the run of modern engines.

     I don't know, but anything fits if you have enough drill bits and needle files.

    Brett

Title: Re: Fox .25 - What else fits this bolt spacing?
Post by: Phil Krankowski on February 25, 2016, 08:43:43 AM

It might be the same as the Fox 35.  How about you measure the spacing and post it since I presume you have the engine.  The Fox 35 is nearly the same as the OS FP20, OS FP25, and OS LA25.  There is a slight difference due to metric vs SAE, but it is close enough to fit. 

I don't have a Fox25 to measure and compare.

Phil

Title: Re: Fox .25 - What else fits this bolt spacing?
Post by: Bob Matiska on February 25, 2016, 02:14:14 PM

I have the 19 version of that Fox; ran it on a Junior Satan about 40 years ago. When my crude measurements showed the same bolt spacing as the Fox 35 Stunt, I hogged out the mounts and bolted the 35 in place. Yikes! Talk about a nose-heavy model, but it flew. Anyhow, my trusty digital caliper from Harbor Freight just showed the mounting holes as .600 by 1.5 inches for both engines.

An OS 25LA I have shows 14mm by 36mm on the mounting holes, both in the manual as well as with the caliper. That's .55 by 1.417 inches, not too far off the Fox. If you use the OS 25, slightly enlarging the engine's mount holes might work if there's not enough play in the plane's motor mount to shift the screws around a bit. Your choice.

Bob in NEPA

Title: Re: Fox .25 - What else fits this bolt spacing?
Post by: BillP on February 26, 2016, 06:27:32 AM

I fly one on a Flight Streak with 9/6 prop. Same mount as the Fox 35 and also shares the Fox 35 muffler...but it runs like a "modern" engine and doesn't break like a Fox 35 or McCoy 35RH.  My main objection with this engine is the venturi location makes it difficult to get your finger over for priming...mine has the muffler ears that get in the way. Otherwise it's an easy starter and great performer.

Title: Re: Fox .25 - What else fits this bolt spacing?
Post by: Gordan Delaney on March 03, 2016, 06:45:21 PM

Hi Brent,
I know without and shadow of doubt that another fox .25 will fit. trust me\

Gordy