Engine replacement question

Is there a direct replacement engine for a Fox 29/35? I currently have a Fox in a fancy pants but I can't get it to run consistantly so I would like to put a new engine in it but I don't want to redrill engine mounts.

A "direct" replacement would be a Double Starr 40, but I would think that the Fox could be made to work. Is the engine worn, or are you just experiencing teething problems? (I have never liked the Fox needle, for instance, but that is easily replaced). Tell us about the engine and what problems you are having. (Engine condition, prop, fuel, needle valve if you have changed it)

The fox is really old and worn it is a .29 and doen't like to start consistently. I can usually get about one or two runs after a lengthy time trying to start it. I thiink the Double Star would be way too much engine for this plane. I already changed the needle valve to a super tiger. I do not have a spinner on this plane so that wouldn't be an issue. I thought maybe an OS 25 FPS do you know how different the bolt patterns are from a Fox? Thanks in advance for any info you can give.

>The fox is really old and worn it is a .29 and doen't like
>to start consistently. I can usually get about one or two
>runs after a lengthy time trying to start it. I thiink the
>Double Star would be way too much engine for this plane. I
>already changed the needle valve to a super tiger. I do not
>have a spinner on this plane so that wouldn't be an issue.
>I thought maybe an OS 25 FPS do you know how different the
>bolt patterns are from a Fox? Thanks in advance for any
>info you can give.
The DS 40 is a good replacement for the Fox 35 for several reasons:
-The mounting holes fit
-The shaft length is about the same
-The weight is the same
-It's power band covers that of the Fox

One of the local guys had a DS 40 powered Fancy Pants out today. Great match for this little airplane. Runs a 10X5 prop just like a Fox.
Steve

The FP 20/25, and the current LA 25 share a narrower mounting pattern than used on OS's FSR 28, which was the leadoff engine for the Clone- making trend. With a "loosened" set of mount holes, the smaller OS engines can sometimes be fitted in the Fox's spot, but not nearly so easily as the Thunder Tiger GP 25 fits.

Another web site for another seller other than Hobby Lobby (Sheldon's Hobyy Shops) showed a much lower price:

THU9020 GP 25 R/C W/MUFF........................ 47.99

http://www.btown.com/sheldons/listing/thu.html

.
Kiwi

The Double Star engines were designed as drop-in Fox replacements. They are moderately expensive, I believe, at about $150 or more. (The DS 40 is not one of the higher powered of engines in its size class; many owners have reported that it may produce less power than afforded by the high end of power ranges seen in exemplary example of Fox's own production.)

There are also a great many Asian Rim engines that started life as clones of various OS Max 25's and 28's that come very close to being a good mounting pattern fit, but almost all are longer, requiring the addition of a thick balsa nose ring for spinner-equipped planes.

TTR25 Thunder Tiger 25 RC Glow Engine .................... $ 60.90

http://www.hobby-lobby.com/ttiger.htm

The Thunder Tiger GP 25 is quite reasonably priced, has plenty of power, is easy to break in and easy to needle. You will probably like it more than you would the Double Star, if you have even one, small, lazy bone in your body.

.
Kiwi

The MDS .25 will drop right in.

Do you know where I could get one and how much?

Hey Kjcitrin, really nice Fancy Pants, look forward to seeing you at the field next week.

The guy with the Twister
Circle Burner