Well, I agree you can't go wrong with Grubee, I own the 53cc with the 4G-1A and after talking with Don he let me split the order up, but I am a loyal customer, and have nothing but good things to say about Grubee, and as far as the HF 79cc, which I also have a bike with a 79cc and the Grubee 5G trans on it, and very pleased with this set up as well, but I had to upgrade the carb, air filter, exhaust, valve springs, and last but most important the flywheel, and I am pleased with both motors, but for a right out of box to bike motor I'd go with the Grubee 53cc, no mods. on mine, and it runs pretty darn good, I hardly ever get on my Zeda 2 stroke anymore, but good luck with whatever you go with.