I got a new 1.48 and spent last Saterday and Sunday breaking it in on a test bench.

I bought 1 gallon of Omega 5% fuel. (pink, castor stuff) I hooked it up to a 14oz tank and ran a Zinger 16-8 prop. Stock glow plug. Bisson Pitts muffler. Engine mounted "right-side-up"

I started it and ran it very rich on the first 4 tanks. I had that sucker burping and farting at around 5800-6000RPM. On the 5th tank, I leaned it out untill it was still 4-stroking, but almost into a 2-stroke at full throttle. Tached it at 6800-7000RPM.

Then, on the 6th tank, I started to lean it out, just a little. I ran it up to full throttle untill the cylinder was too hot to touch, and then backed it down to an idle. I had the low speed idle backed out 4 whole turns. This helped to cool it down quickly. It took about 30-45 seconds too cool the cylinder down. I could rest my fingers on the side of the cylinder . It felt only slightly warm. Then I would run it back up to full throttle untill it was nice and hot. Then back down to an idle.

I ran the 7th and 8th tanks the same way as the 6th one. Slowly leaning the high speed out. Then letting it cool down with a nice, rich low end.

It is just beyond 4-stroking. About 1/2 turn into the 2-stroke mode at full throttle. But, still plenty rich.

I finished out the gallon and it is turning 8000-8300RPM.

I think I might get another gallon and keep running it on the bench.

I'm impressed so far. Granted, I havn't leaned out the low speed yet. I have no idea if it will idle consistantly. Or if it will transition well.

But a Zinger 16-8 at 8000RPM after 1 gallon ain't too shabby. 'specially at Denver altitude. 5500 feet.

Almost forgot. I noticed that the remote needle valve and bracket is vibrating at high speed. The engine would vibrate and cause the line between the carb and needle valve too foam. That would cause the engine too lean out and speed up rapidly. Fortunately, I was right there and was able to lower the throttle setting before the engine could run up too fast. I replaced the stock fuel line between the needle and carb with some mediun blue fuel line and moved the needle valve to another location. I took it off the engine and mounted it to the bench. This solved the problem. This could be why some guys are having problems with this engine. The needle valve vibrates and causes foam in the line. Maybe try moving the bracket to the firewall, and replace the fuel line between the needle and carb with a larger size.