YZ85 Big Bore Kit

October 16, 2007 7:30am

Glenwood Springs Colorado – October 17, 2007 -  Marvin Claridge of  Kustom Kraft Performance Inc. has announced the release of their 2007 Yamaha YZ85- 110cc Big Bore Kit.

Kustom Kraft Performance classifies this kit for expert riders only. This is a huge increase, 30% more displacement for a massive increase in low end and mid range. If you need more power but aren’t ready for a 125 or 250 this is a viable alternative to spending thousands of dollars to step a class or two. With this package your YZ85 will rocket off the line and out of the corners like a 100 on steroids. 

The 110cc big bore kit is a straight forward modification. KK machines your cylinder and installs a special hardened moly/steel sleeve. They then hand match and port your cylinder for the new configuration. The cylinder is bored and finished to precisely fit the new piston and rings. 

Your head is re-shaped to accommodate the 54mm bore and squish band is adjusted to provide the optimum combustion. The entire combustion chamber is polished to a mirror finish. To be sure of good head gasket seal the sealing surface is machined smooth and flat.

The kit is supplied with a brand new piston, rings, and clips. Plus the entire top end gasket set. Kits are done using your cylinder and head in about a week.

Because of the huge 54mm bore size case modification is required. It’s not a big machining job, but because you don’t want to get any shavings in the crankcase it’s recommended that you completely disassemble the bottom end and then do the cutting or grinding to allow room for the larger piston.

Kustom Kraft will do the machining for you at a reasonable cost, or they can do the complete tear down and re-assembly if you prefer. Call and talk to Marvin about your needs toll free 888-697-4343

Kustom Kraft Performance has been around for almost 40 years repairing, sleeving, plating cylinders and designing big bore kits.

Kustom Kraft Performance has other kits and other sizes for the Yamaha  YZ80 and YZ85’s at http://kustom-kraft.com/YAMAHAKITS.html