Background: retired certified engineer with several design patents and decades engine experience.
The good: this is a great looking model the machining is top notch. The best looking hm out at this point. Everything beautiful made, great display.
Opportunity for improvement: Do not expect this to run well without significant tinkering based on my experience. This did not run at all out of the box, and has taken many hrs removing bugs to get it to stay running without randomly sputtering out.
-the piston ring needed replacing (spare included)
-the ignition timing was a good 30deg advanced, causing difficult running. It should be set at top dead center. This is not easy to achieve, given points design, it's a trial and error.
-the point spring rubs on the base of motor and the valve rod, wearing thru the rubber insulation causing intermittent shorting.
(I narrowed the spring to add clearance and added shrink tubing to insulate better.)
-the intake valve may stick causing loss compression. (I increased valve spring tension)
-the carburetor is extremely finicky and one has to quickly change settings at times to keep it running, esp during warmup.
-the recommended 25:1 gas oil mix may be too rich, upon pulling head I found way too much oil and carbon in there. I run 75:1 mix with non-ethanol gas and keep all oilers full for best results so far.
I have about 3hrs total run time and things seem to be breaking in better.
I bought additional ignition, plug, carb, head, ignition wiring, battery, during my attempt to diagnose the sputtering out, but found no smoking gun. (I've noted the fuel is pushed half an inch down the line from carb, so something is causing back pressure, maybe a sticky intake valve still)
I removed the high speed lever as I only run slow mode and the lever can contact the points wiring.
All in all, nice engine, not recommended unless one has motor experience if intending to run.
Needs improved adjustable ignition, more spare piston o rings, stiffer intake valve spring.
If your willing to tinker and have experience, recommended. Thank you