Happy hillbily
Member
- Location
- Uwchaled, North Wales
I've read somewhere about the 6610 series 11, that some punched well above their hp rating, but the majority couldn't even muster the advertised hp, so when they brought the series 111 out they derated the 6610 to 80hp and badged it the 6410, and de fuelled the 7610 to 90 hp which gave the 6810.