FOX .049 ??

I believe it is the .07.  If so, the other side of the crankcase may have a burnished rectangle.

George

The piston is 0.389 and has a large dimple in the center , ball and socket has a lot of play . getback George no marking at all on the engine

Call Fox as they probably still have the parts. It might be cheaper to just go on Ebay http://www.ebay.com/itm/FOX-049-074-NEEDLE-AND-SPRING-SET-NIP-/291677629775?hash=item43e9576d4f

           That needle valve and spray bar was used on the .15 bb, the .19 bb, .25 bb, and the plain bushed 4 bolt backplate .25. It was a very common part. Plugs are a bit hard to come by and they're very unreliable. It may light but it will run and just shut off. I drilled and tapped one for a standard plug and it surprisingly worked well. Ken

Thanks for the Info Ken ,, I used the reset tool for Cox 049 to set the ball socket not much change in the rivet dimple but sure brought the comp. up considerable. I probably have one of those engines with a needle in it and will try to see if it will run before I purchase anything for it /pics done with nice and tight adjustment Eric

I was gifted a Fox .049 from Larry Renger and it came with a bronze threaded insert to allow Cox heads to be affixed. You may want to look into that.

Ron

That sounds like a special made insert , isn't the head thread 1/4-28 and I don't know about the Fox I cant get the head off as of yet don't need to ... but I did read where Ken said he changed his over and it ran for him where it wasn't before . The dimple in the piston is enough to damn near foul the ole plug , may be I should get the head off and index it before I start cranking +++ just happy I got some comp. back and hope it holds up .getback

The ring that Ron mentions was made by Bob Matte. This is not a inexpensive part. My solution was indeed simple, but it wasn't nearly as powerful as the stock plug. It did run reliably well and started easily. That was more of a plus for me. As I mentioned, the stock plugs are getting harder to come by and just because it lights doesn't mean it's going to work well. I'm quite shocked you were able to reset the piston. It generally shatters and I wouldn't make a habit of doing that. This isn't quite the same metallurgy as a Cox piston nor is it the same quality of metal. The dimple on the piston isn't from the rod poking out of the top, it was made like that. Ken

Thanks Mark I have seen that pic before and confirms its .049, Ken maybe what saved it was I did the reset on a piece of 2x4 pine here in the house it takes more tapping but its not as cold as the shop right now lol.Maybe just luck too one more question does the Fox have a cyl. gasket this one don't. Eric

Eric,
You didn't wait very long to get the Spectre dvd, did you?!
Chris...

NO Chris didn't ,, I should have waited but I couldn't because it was so cool !!!! I wish it showed the doll coming off the back of the plane that looked like a case of hitting the tail feathers or depollute upside down /?  waiting on Duke now getback