The UPS man brought my father's day present yesterday, a new Irvine .53. Now with TiggerinVa's help, I figured out what those little black parts on the screw were. The carb is nicely installed (I hope), now to the questions. The only fuel I have is Wildcat Premium 10%, with 16% Syn/Castor oil mix. The instructions suggest FAI or 5% Nitro fuel. Should I get some new stuff for this engine, or can I just add enough castor oil to bring it up to the right mix? What prop should I use, I have 10", 11" and 12'ers to choose from? There was a black glow plug in the box with an Idle bar, should I just use that one or get and OS 8 when I get the new fuel? I also have a new Magnum .52XLS ready for break in, I guess I can just use the same stuff for it also, except I'll use my 10% fuel for it.

I use 17% synthetic, 15% Nitro feul, runs great.
I'd try the glow plug, I borrowed a similar one, and didn't notice much difference (if any).
12x6 ran great for me, for breaking in.
Its a simple engine, doesn't need much attention.

IF you don't over-lean it, the 10% won't give you any problem,, this engine needs little break in.. I have mine for over a year and to this day has never dead-stick on me.. I'm using 5% Nitro w/18% Synth/Castor blend (I live at sea level.. Inidiana is not much higher, but at least is higher than 12 masl, at our field

Thanks for the replies, guys. Today I bought a gal of Byron's 5% but with only 16% oil mix. How many oz of castor oil do I need to add to bring it up to 20%? MY Magnum .52XLS instructions say use a 10X6 for breakin, same for the Irvine? I have a 11X5 on it now. Too many people here now to try it out. Maybe tomorrow.

You'll need approx 6oz of castor to bring your byron up to speed.

10-6 is fine for break in (too small for flying), but that's OK...you want a smaller prop for break in anyway.

Did the engine come with any instructions? UPS man run off with them?

What was wrong with the plug that came with the engine?

Many on here including me found out very quickly that the Irvines are flyable after about 20 minutes. They run very well on 5% nitro.
Also a 10x6 is not nearly enough prop, not even for break in. If I remember correctly they recommend a 12x6 for the break in.

I burned wildcat 10%, with a 11x7 for the first 2 (I think it was 2) tanks and the first several flight after that. Then switched to a 12x4 prop and now running 5%. Not had any problems at all.

I wouldn't use the 10 x 5, leave the 11 x 5 and break it in for about two tankfuls.. adjust the needkles and go flying ...
Irvines like big props anyway.. i broke in mine with an 11 x7 and flies like a charm

The .53 really doesn't need much for break-in. All I did with both my 53 and 46 is add fuel, run a half tank on the ground to make sure it'll hold a slightly rich needle setting then refuel and fly. Personally the smallest prop I'd go with the .53 is an 11x5. Mine turns a 12x4 wideblade prop at 13.2k set for flying, on 5% Omega.