livingoodnathan
Member
- Local time
- 3:58 PM
- Joined
- Feb 15, 2019
- Messages
- 57
So if anyone read my last thread I'm looking for a spring project and I want to put a big bore top end on my pk80 race engine. I have drove myself crazy trying to find something that isn't going to.take a lot of modification like the stihl 660 and take me out of riding for weeks if not months. we'll I think I have found it. These come in two sizes, an 85cc kit (50mm piston) and a 102cc kit (55mm piston) they are for a vespa 50 2 stroke scooter and the stroke is 43 mm. With my pk80 the stroke is 40mm so with the right combination of gaskets a 43mm stroke is going to work right? And the wristpin is either 10mm or 12 depends on the year of the scooter but need to look further. But, if.it does come with a 12mm pin I can bore out my pk80 rod to 12 yeah? Or better yet put a sleeve inside the 12mm pin to make it 10mm?? What do you guys think will this work as a bolt on application for the most part?? I realize if I go for the 102cc I may have to mill out the crankcase a bit but what about the transfers? These kits have two transfers on the sides divided up into 5 or 6 I believe. It looks close. Also the 102cc version has a third boost port will this be ok? Will I have to mill out my case for it? Would love anybody's input and knowledge as this is my first time stepping into the realm of bore kits. This is about the only thing left i want or can do to my bike. And i want a little challenge but i am no welder and the stihl 660, 440, exc. Are more than I would like to take on. These kits look legit. Hopefully y'all agree or atleast agree that is might work lol. At less than $150 dollars I'd be willing to try for 102cc and share my experience.