Can someone list the hp for all YS engines? I guess because the pressurised fuel pump that every engine is dif. or not the same as the next?

Horse Power ratings are fairly useless as you don't know what criteria was used to establish it. I like Fox's method, they tell you that a particular engine will turn a certain sized prop at a certain speed. For example a .46 ABC will turn a 10x6 at 14,400 rpm, I much prefer for it to turn an 11x6 at 12,000.

www.ysperformance.com

Look under the FAQ's

finally redid the old ys site! looks good, thanks for the info can773.