RE: ADVICE NEEDED Supertiger and Magnum Quality
Stay away from the Magnum 52 XLS two stroke. The carb. on it is N.F.G. along with the bearings and bushing fit on the con-rod / crank pin. I replaced the bearings on mine and was going to replace the con-rod bushing as well, mine came from the factory .005" loose on the crank pin. I had the engine apart when it was new. The crank pin was -.002" on the nominal diameter and the bushing was +.003". Pretty shotty machining I.M.O..
No sense doing it now because I now have slop in the wrist pin as well, probably due to the loose crank pin fit, so I'm just going to run it till she blows! The engine is a (powerful) P.O.S. .... waste of money I.M.O. It will be a long time before I purchase any more Chinese "junk". You may want to consider a Thunder Tiger Pro 46. Although not as powerful as the 52, it is far superior in quality with one of the best carbs. in the business and is reasonably priced. The TT 46 probably has more grunt than the ST 51.
What type of plane are you planning to put the engine in?