Hello everyone! Newb here, I own a 79 yamaha chappy lb80. This bike has over 12000 miles and i think the engine is worn. recently i noticed a lack of power and compression usually after a long ride. Everything is clean, sparkplug is new, carb rebuilt, clean airfilter and exhaust. In low gear at full throttle i was able to keep the bike from moving by keeping my feet planted. Ive talked to several people saying i probobly need to bore out the engine. But have been told no bore kit exists for this bike. And would probobly need to find someone to do a custom job which could run up to 1000$ or more. Any advice on getting more power or if any bore kits exist or which cylinders and rings i should look for? thanks!