I am pretty sure it is in the Zenoah manual which is here:

http://www.horizonhobby.com/ProdInfo...nes-manual.pdf

If memory serves, it's something like 1.6 HP

I can tell you this. If you get one from Ralph Cunningham (RCIGN1) his are converted to electronic ignition are with a Mezjlik 18X6 prop they put out 17lbs of thrust and weight right around 48oz's AUW

His prices for a new coonverted G26 are around $400 shipped. Just shoot him an email or PM