Re: B1 rep problems - new guy, need help.
Wow, a patch on the bottom of the engine, The cases have to be air & water tight, if it was leaking on the bottom I would not buy it, cases are probably cracked or warped, and leaking water. My C1 new was $450 USD. New cases are around $40, and then SKF bearings and crank seals, and $40 plus to rebuild the water pump. Your main problem is where do you get parts?? If the cases were good you could go to an air cooled cyld and head, and leave the water pump area blank. They don't make parts anymore, hard to find even here in California USA. Pocket Bike Parts in Florida USA has parts, but cost alot to send them to you. I have 13 bikes and 5 project bikes going right now, lol.
It's cheap to rebuild a Cag. For $80 you can get a big bore kit with 15:1 winged billet alum head & cap and hp ported cyld w/ piston, rings, pin, clips and rod bearing and full gasket kit and full circle racing crankshaft, even a China spark plug. All you need is maybe new crank bearings and case seals, and you have a brand new engine.
My advice for you is get a PayPal account and buy direct from China, most free shipping world wide. Search eBay for parts, and I also deal with AliExpress.com and Banggood.com for some parts, direct from China. Search, 47cc, 49cc Pocket Bike Parts and Engines on eBay and see what shows up. Here is my custom build Lucky 7 Cag with Winged head engine.
Empty Pockets Racing: The difficult we do, the impossible takes longer.....