63mm BBK By geh4444 (Read 292 times)

[geh4444]

Anyone install a 63mm kit ?

[geh4444]

Got the 63mm kit and head installed. I bored the case out with files and grinding wheels . I went for a short ride . I have an oil leak either from the variator side crank seal or its coming from the valve cover . I may not have tightened it down enough. It was 2am so ill check it in the morn. The scoot ran great and felt really strong. I have 18:36 gears in at the moment . I should be able to turn them with the extra hp from the 63mm kit. Hoping to be able to hit 70mph easy , possibly 75 top speed or higher.

[geh3333]

Update: I ended up buying a bored out engine case and doing a new 63mm build bc I had a bad oil leak and I also had a cracked piston skirt after the last one. I went with the new Roller rocker arms , taida high torque starter, 18:36 gears, another new stock crank , 15 gram roller weights , taida variator and clutch assembly, oil cooler and I ordered a koso temp gauge . I also bought a set of wider and taller 100/90-14 tires, just have to put them on yet. This thing runs great , I also switched from a junk cvk carb to a maikuni flatside. The throttle response is so much better along with the throttle range . No more dead throttle spots and so much more throttle on the big end. I clocked it at 72 mph at 5,000 rpms and had to slow down bc I had a car in front of me. I used my phones gps speedo app so I knew it was accurate. I weigh a good 225 and I'm sure this thing will hit 75mph .

[brutus413]

I was able to find a 63mm BBK that didn't need the crankcase bored out and dropped it into my 157QMJ. The second part of the puzzle for me was final gear ratio. With the added HP I upped the final gear ratio by 30% and was able to get up to 70mph on the flat. Ran for about 750mi (1250Km) before the crank went bad. That was 15 months ago and I just haven't had time to get into it. Finally took it to a mechanic and they want to replace the motor. Not sure that's necessary, but the lack of free time is making it a tempting option.