I just bought a Sig Skyray from my nephew that has flown exactly 1.5 times.  It's the American Classic modeler story: kid wants plane, dad builds plane, kid wants to fly, dad says "no, I'm going to fly it first because you're going to crash it".  Then Dad crashes it.  The first flight was me, doing a checkout flight.  Oh, if I'd known to stand inside the circle with the student pilot, holding onto the handle with him!

So I have some questions:

The engine is an OS FP 20, with an unknown amount of break in, and has sat for 10-15 years gathering dust.

It has loosened up a great deal with just some after run oil.  My temptation is to just make sure the needle valve and tank aren't gummed up, get it started, and run it a bit rich at first.  I'm assuming from the lack of "squeak" at TDC that it's got an iron sleeve -- is this so?  Is it Schnuerle ported, or loop scavenged?

What's the right length line for this?  I have a nice pair of 60' lines made up for a plane that I'm not going to fly for a while.  Is that going to be too long for just going in a circle?  Should I just go to 52' lines now?

Finally, the hinges are CA hinges.  They move pretty freely, but they're not really really loose the way that a proper pinned hinge is.  We're pretty highly motivated to get this in the air tomorrow (nephew is visiting and wants to get at least one flight on the thing).  So I'm not really thrilled about cutting out the hinges and going to pinned.  Just how free is free enough?  Ultimately I think the thing is going to get a great big thread hinge, or I'll whack it up and put in pinned hinges, but I'd sure like to fly tomorrow.

Thanks Brett.  I'm glad you said that, because I forgot that I'd asked and I went and ran it already!  Fortunately that's pretty much what I did.

Now to balance my one-and-only 9-4 prop.  Maybe I should go buy a couple.

"" Is it Schnuerle ported, or loop scavenged? ""

They are one in the same  Dr Schnuerle  invented "loop charging"

Argh.  Not only do I get loop scavenging and cross-flow scavenging (with a baffle, in case you've lost faith in me), but I forget that I get it wrong, and never double check!

I had the right pictures in my mind -- really I did, honest.

Dr. Schneurle also invented the two-exhaust two-bypass scavenging method used in the Cox 049 and many other 1/2-A engines -- but I can't remember the name of it.

What's the fuel consumption like on those things?  It's got a 4oz tank, into which I put 2oz for the first flight.

It seemed like it stayed up there forever, but then it had a problem with the bellcrank mount* that didn't evince itself until the plane was in the air, so I have to consider myself lucky to have gotten it back down on the ground in one piece (and now I have to tear into it to fix it -- boo hoo!).

* The nut had fallen off of the mounting screw, and the bellcrank rode down on the screw, causing the leadouts to catch on the nearest rib.  This, in turn, made the controls tend to stick on up or down -- fortunately I could jerk on the plane to get it past the sticky, I had a little bit of travel around neutral, and things didn't fall apart even worse!  So the first two laps were a bunch of dips down to the ground followed by zooms (from me jerking on the line), then an involuntary wingover, then I got it under control.  Once I got the plane settled the balance of the flight was a study in trying to fly really smoothly with white knuckles, until the fuel ran out.

They get good fuel mileage  the 4 ounce tank you have will be  more than enough LOL

Randy

What's the fuel consumption like on those things?  It's got a 4oz tank, into which I put 2oz for the first flight.

It seemed like it stayed up there forever,

   2-2.5  oz of 10% is about right for a full pattern and a well-broken-in engine.

   Brett