RE: Saito 180 with perry pump
I ran 5% nitro in a 1.80 Moki and it sagged and shut off at high rpm too, to the point of piston seizure.
Moki recommends a K&B 1L plug, no nitro and a fuel mix with 20% castor.
My Moki now turns an APC 19x8 to 7500 rpm, and it ticks over at idle. My tank sits right behind the engine.