Before we start, we need to be clear that the Yamaha Fino will never be one of the top choice for speed geeks. We found after our installment of the engine modification that the Yamaha Fino becomes hard to drive at higher speeds. Some moments the Yamaha Fino was outright dangerous to handle. After we examined the cylinder of the Yamaha Fino we came-up with the idea to do a bore-up to 63mm, the stock bore of the Yamaha Fino is 55mm. Changing the bore from 55mm to 63mm will change the Yamaha Fino from a 114cc to a 189cc motorcycle.
After contacting some of our sources for accessories we found a manufacturer who produces a complete set, which includes a 63mm Ceramic Laminated cylinder, a high performance 4-valve cylinder head (the Fino comes standard with only 2-valve head), 63mm Piston, high performance racing camshaft and the materials to make this all fit and assemble.
This tuning set is originally for a Yamaha Nouvo, but as the Yamaha Fino shares the same engine we expect not much problems mounting this onto our little Fino. For the carburetor we replaced the Mikuni BS25/1 with a Mikuni BS32 which we had on stock, this carburetor originally was from a Yamaha XJ400 bike. Normally the 32mm Mikuni would be a bit to big for the 189cc but we decided to go for a smaller jet needle and restrain the air intake a bit.
After we had the Yamaha Fino rebuild, and fitted with all the superbike engine parts we started the little lady. The first thing we found was that the exhaust as not big enough to give it a go, the exhaust was easily replaced with a more aggressive model and now the little lady did not sounded so little
Doing some test driving, we found that the wheels of the Yamaha Fino are not balanced to go that fast. After we did some professional tire and wheel balancing. We still had difficulty driving this scooter at higher speeds. Knowing that the engine could easily bring this scooter to speeds around 180km/h we had problems of reaching speeds of 120km/h as where it was almost impossible to handle the bike safely.