Okey, you older guy's is this good.
I just test flew my newest Kvick Fli today with a NIB K&B 61 PDP by Clarence Lee.
I ran it fat with 27% castor 5% nitro on a Robbe 11x8 and got 12500rpm, it should get 7-800 rpm more when leaned out in a couple of tanks of fuel.
It idels around 3400 rpm and it's rock steady.

I also have some of the other engines in this topic.
OPS 60 with carbon robbe pipe.
Rossi 60
Webra 60 RE
webra 90 RE
HP 61 several of them

Alot of these are NIB.