I am not sure what the genuine BHP rating on the CV's is, but O.S. tend to 'undershoot' the mark quite a bit, perhaps the CV is already a .75 HP engine, so increasing it to 1hp is less of a step than from 0.5-0.75...

I'm thinking that If I decide to go down the port modifying track (I have dozens of diamond burrs, but haven't ever seen diamond files, where could I get some?), I think I'll swap to a kyosho GX15CR conrod, it's about another MM thicker, yet the same length, same big/little end hole sizes from memory.

For the time being I'll just leave it as is, I have no idea if my mods have worked, or how the engine goes, still waiting on some engine mounts...

I ported the heck out of the stock GX15 engine e few days ago, which will be getting a run in today, so wish me luck!