Shark .15 and Taming the .15x

[C.T. Schaefer]

Today I finally 'got there' with my Shark .15 combo. The past few years I have been going retro a bit. I've been able to find kits of some of the planes I built 40+ years ago and enjoying them. I looked for years trying to find a Shark .15 on the bay and then noticed that Walt Umland makes the kit. Got it. Beautiful. Built it. Looks great. Weighs one pound, no flaps. Since my original Shark had a Fox and I had one, that's what is up front.
  First flight with Master 7x5 the motor was screaming and the nose was a blur. Not good. Next I tried an APC 7x6w. Much better, it held the revs down so the nose was not buzzing. The gas tank is the perfect long skinny 2 oz. job with uniflo. Unfortunately 2 oz. was not enough to do a pattern. Also not much room up front for a bigger tank. There have been several outings this winter and to shorten the story a bit here is where we are now. The .15x is a hot little motor and the early ones were supplied with a .040 head shim. I found that mine did not have that so I added an extra .010 shim to ease the compression a bit. Todays outing had a Master 8x5 Scimitar and a venturi reducer ( .250 vs .270) and a spraybar from a later model Fox .15bb.
   Result:  Smooth 5 3/4 minute run time at 4.6 sec. on 58 ft. .012 lines. Full pattern with crisp corners. Me happy!   Sure, I could have used an LA but really enjoyed getting it to run properly in full nostalgia mode!!   TS

[GERALD WIMMER]

Hello Interesting hearing about your experiences of the 15X on the little Shark. I wanted to relive my past as well and bolted a Fox 15X to an old Airsail Showman and was surprised by the power it made even with a free flow muffler. I used a 7x4 to let it rev as I had read they liked. Then put another Fox 15 on my new Showman (with Flap too!) but this was not an 'X and it was very sad and got pulled off .
I remember my younger brother ran a unbushed early 1980's Fox 15 on yet another Showman back in the early 80's and it was nothing like an 'X' what a difference !
Suppose this is why some people like exercising with Fox 15's 
Regards Gerald

[john e. holliday]

I remember back before the 15X the Fox .15 was hit or miss it seemed like.   Older gentleman in our cluc, George Watkins loved them.   He would even take the ones people were having trouble with and get them running.   I asked him what the secret was and he stated "Break in".   Tommy, glad you are having fun again or still.   Some of todays CL's don't know what they missed and then again maybe it a good thing they did.   

[Juan Valentin]

Hello CT
                 I`m painting mine at this time and would love to see a picture of yours. I also have a Fox 15X that was given to me and if mine comes out nose heavy with The Veco .19 I might give the Fox .15 X a try.
                                                                                                                                                          Juan
 

[Andre Ming]

Gentle reminder:

You're not allowed to say nice things about the Fox 15X on this forum. There are too many Fox 15X Hurl fanatics that never learned how to handle glow engines that resent those of us that can.

 

Andre

[Larry Fernandez]

Gentle reminder:

You're not allowed to say nice things about the Fox 15X on this forum. There are too many Fox 15X Hurl fanatics that never learned how to handle glow engines that resent those of us that can.

 

Andre

Sorry Andy, but you could not be more wrong.
Not one “Hurl Fanatic” has ever bad mouthed a Fox .15X.
It’s the Fox .15 Slant plug that we take great joy and amusement in “Hurling”.

Larry, Buttafucco Stunt Team

[Andre Ming]

Hi Larry!

Well... the engine I refer to IS the slant plug Fox 15X.

http://sceptreflight.net/Model%20Engine%20Tests/Fox%2015X.html

BTW: The name's Andre not Andy. Andy never has been my nickname.

Andre

[john e. holliday]

Well Andre that could be said about most people that bad mouth Fox engines.  I've had a couple that gave me fits until I got them broke in.  Even when I was Flying RC I was the go to guy for operation of Fox engines.   

[Al Ferraro]

Hello CT
                 I`m painting mine at this time and would love to see a picture of yours. I also have a Fox 15X that was given to me and if mine comes out nose heavy with The Veco .19 I might give the Fox .15 X a try.
                                                                                                                                                          Juan

Here is the photo of C.T. Schaefer Shark .15
Al

[C.T. Schaefer]

Thanks for posting Al! My technology is still 20th century.
PS  the tank in the picture did not work out. The 2oz  Brodak/Perfect tank fit the bill.  Let us know how yours works out.   TS

[Bootlegger]

 Al, what is the transparent covering that you used on the 15 Shark, it looks real nice...

[YakNine]

I have had a lot of luck with my 15x's , mine seem to  run really well with 8x4 Master Airscrew GF3's & Glo Devil short plugs. The ST needle valves are an easy install and hold their settings much better than the Fox needles do. I run mine uniflow and launch in a wet 2 stroke. Power Master GMA 10/22 with s little extra castor & a few flips with your finger over the Venturi to prime & your good to go. T J

[Jim Kraft]

I also had a Shark 15 with a Fox 15X. I flew mine with a Top Flite 8-4 which worked really well with the spacer in the head. It ran a great 2-4 break and had plenty of power. I built mine with flaps just because it was my first flapped plane. I built it back in the 60's and was flying it a few years ago when I ran out of fuel in the wing over and it did not recover. I gave the engine to a friend when I finished up a racer for him. That engine had hours and hours on it but still ran great. I did fly mine on 52' lines.