Kit of parts arrived in 15 days from China, very well packed. Instructions were fair at best. Illustrations were mostly used, but the needed details for carburetor and valve adjustments were lacking and/or confusing. Assembly took about two hours , then another 3 hrs to actually get the engine running after trying many combinations of adjustments. I used pure naptha as the fuel, and the engine seemed to like it. I'd give the fit and finish an 8 out of ten - burrs were present on one side of many of the through holes , as well as excess metal on some of the smaller parts. Also, some of the parts required a little sanding (a small piece of extra fine sand paper was included). I also had to modify the HV wire to make better contact with the spark plug and adjust the points for improved contact. Overall, I'd say a pretty nice model for my first miniature engine build. I'd buy another Retrol again.