probably a better question than 'turbo, ports etc' is how do they measure their HP - and is that the same standard as everyone else (if there is such a thing as a standard)
RB dont make claims for their HP, but on the track they seem to keep up! so if they said they had 1.8HP would that mean that they had 1.8HP or that the way everyone else measures HP is wrong, or they dont have 1.8HP and they are more like the claims of others 1.35HP?
for my A$0.02 (whats that... about US$0.01 so its a devalued opinion!
) i dont think anyone actually knows for sure what HP their engines are putting out.
i reckon novarossi said ok this engine make 1HP the next design is more powerful so lets say 1.15, then the next one 'hmm' 1.3, oh the JP is a bit grunter then the original so lets say 1.35..... and so it goes the estimations of HP keep climbing