Hi!
24x10 is OK!
Possibly a little too small if you fly att sea-level and use a cannister silencer. MVVS says a Mejzlik 26x6 carbonfiber prop turns 6100/6200 rpm using the MVVS No 3204 cannister silencer and a 24x10 Mejzlik turns 6400rpm with the MVVS 3207 silencer.

For comparence I use the first variant of the MVVS 45cc engine with the aluminium case (100 g heavier than the newer one with magnesium case) and use the small MVVS cannister (No 3206)
I get 6600rpm both with with a Mentz 24x8" and Graupner wooden props and 7200rpm with a top-Flite 24x8" prop. A 22x8 prop is way way too small for the MVVS 45cc gas engine and should be for the 58cc engine as well.
I run my engine on 2,5% all synthetic oil and 95oktan lead free fuel. Running in was done on what MVVS recommended; 4% all synthetic oil.

No lenghty running in time is needed on any MVVS engine, be it gas or glow!! This must be a severe miss understanding!
The engine should turn top rpm after just a tank or two.

MVVS uses the Brisk UR-17 plug for these early gas engines. The new one uses the much smaller NGK CM-6 plug.
4,8V-6v, 2000-2800 mAh NiMH cells is used for ignition. I use 4,8V , 2500mAh AA GP cells soldered together.


Check the spark plug function by removing the spark plug and hold it against the crankcase ...as you turn the prop (Hold it with a pair of rubber glows) you should get a spark as soon as you turn the prop.