I haven't seen a Fox 19 in a few years, but,

A) I'm pretty sure it needs a head gasket.

B) The play you describe can be better diagnosed by pulling the backplate off and observing the crank pin in the connecting rod while turning the engine over. If you can see it shift as you wiggle the prop back and forth, it's worn. You could even measure the hole and pin if you have a caliper. Another good thing to check is the wrist pin and upper connecting rod hole for wear.

C) Liners protrude above the cylinder. the head and gasket hold them in place.

Having said all that, it might be worth just throwing a head gasket in there and see if it runs.

You are probably feeling a 'light snap' because there is no continual load on the rod whenever its not running.

A lot of this will disappear upon starting - not that I am saying it will be a good thing but I have seen many engines with worn con rods that work better than they have any right to.

Just clean it up and give it a go mate.

   Agreed, just put a head gasket in and see how it runs. The make haste to get a second model going, bigger (like a Flite Streak or Skyray 25) with a 25LA.

     Brett

  Now where could I get a head gasket?

Randy Smith is the 'go to man' here.

I'd get a gasket, but drill a 1mm oil hole in the bigend journal of the conrod (chamfering the inside with a 4mm drill bit and wet n dry). Then simply replace the rod back to front. - I've done this on a my Thunder Tiger 25s and pretty much all of my Fox Combat engines with surprising results (you could even drill a 1mm hole in the wristpin journal if you wish!).

Just make an indentation with a centre-punch first at the dead centre of the rod end (a little offset is good as you want the fuel mist to coat the bypass side of the conrod on the compression stroke ideally).

The conrods do wear oval eventually, although from my own experience it's always tapered as the crankpin moves out of the bigend under load anywhere between about 5-15thou. The latter being on a particularly worn main bearing/crankshaft - a telltale sign of this is a 'runny nose' or unburnt fuel running out of the front of the engine between the crankcase and prop driver!

They all start doing it at some point or other......


Tim

I just want to add that maybe you are looking for a head 'gasket' that is already there.  Typical gaskets for heads are really a thin aluminum shim that is pushed into the head creating a seal.  If you see a paper thin aluminum washer in that groove in the head that IS your gasket.  To add any more is to lower compression in an already low compression engine.  Cross torque it carefully,  shoot it with some light air tool or Marvels and go fire it up with some sloppy-oily fuel.

Dave