Originally Posted by
dan_vector
These are very good. Seen one going last weekend. It's a rebranded Max Power engine which is novarossi based but based on a couple generations back when novarossi's were very good. I believe it's also in a Rex crankcase.
Yes, the 12 and 21 engine based on Rex. I have 21 engine which using 7x19x6.3 very old style front bearing. But, the engine if fully hand modify include the crank case, crank, sleeve and piston top. Power is good and run time is good enough for 5 mins. I think the 12 engine is pretty same situation.