response to several posts:

The 45cc I found just a tad shy of the MVVS 43cc powerwise, after I fitted the second front bearing that the crankcase had room for. I loved this engine/ignition combo.

About the RCexcl ignition:
This has been discussed in several threads, and no one seems to know exactly how to set the ignition properly. So I invested in a timing gun, built a test bench and did my own research. Hang on!
below 500 rpm, the ignition does not retard! So flip the prop slowly, and she will bite.
above 800 rpm, the ignition retards a full 21 degrees.
at 1500 rpm, the retardation is lessened up to ~3500, when retard is nil again. A very nice range that allows excellent throtle response without any power jumps or surges.
up to 8500 rpm, the ignition fires as set by the pickup!
above 8500, there seemed to be a very sligt retard again, catering for the higher squish velocities encountered in the combustion chamber.

On the 26cc engine not much good to say:
using an MVVS 26cc, rpm on 18x6 props is in the 9000+ range; 'nuff said about the performance, which is very very much below par. Piper cub fodder IMHO. Add the fuel puddling problem, and this engine is out of my book. There were more problems that I will not mention here. Maybe they have been addressed.
I used a syringe piston (rubber) covered spatula for the choking to reach into the confined space between firewall and carb. That worked fine. The choke plate off a Ryobi engine also would do the trick.