61mm BBK that does not require case boring!

babblefish · Post by **babblefish** » Fri Mar 03, 2017 10:40 am

While looking for stuff on eBay, I ran across this bolt-on 61mm BBK that does not require any case mods (so they say). This is for 150cc engines only as it uses a 15mm wrist pin. So used in a Buddy 150, and assuming a stock 57.8mm stroke crankshaft, your engine displacement will go from 147cc to 169cc (not sure how they get the 171cc in the ad). Not too bad for a bolt-on affair. A carb rejet will definitely be required though.

NOTE: even though the title says "GENUINE", they are not implying that this kit is for the Genuine brand of scooters. And best of all, they're based in the U.S. so shipping won't take forever.

http://www.ebay.com/itm/NCY-CYLINDER-KI ... Zv&vxp=mtr

MGM · Post by **MGM** » Fri Mar 03, 2017 2:19 pm

This Kit has been around for awhile, and from several sources
https://www.scooterworks.com/NCY-Cylind ... P1028.aspx

babblefish · Post by **babblefish** » Fri Mar 03, 2017 8:41 pm

MGM wrote:This Kit has been around for awhile, and from several sources
https://www.scooterworks.com/NCY-Cylind ... P1028.aspx

Thanks, I didn't know about it. Since the text between the two ads are the same, I'll bet the seller on eBay is scooterworks. The only thing about this BBK is how thin the cylinder wall must be to allow installation without boring out the crankcase.

dasscooter · Post by **dasscooter** » Fri Mar 03, 2017 9:41 pm

I've been told the way they did it was removing the piston skirt.

babblefish · Post by **babblefish** » Fri Mar 03, 2017 10:13 pm

dasscooter wrote:I've been told the way they did it was removing the piston skirt.

Makes sense. That's a known performance mod that even Ducati uses in their production bikes. Though I have to wonder what the piston/cylinder life will be in this particular application.

dasscooter · Post by **dasscooter** » Sat Mar 04, 2017 5:25 pm

Personally I'd rather bore the cases or run a smaller kit.