Call him and ask. Some bikes need case mods and some don't. I think the YZ does, but Eric will tell you for certain. I had to send my complete motor.
Eric's Number:
1-630-289-5645
It's usually best to call him first thing in the morning - 8:00 or something. It can be easier to get him on Saturdays as well. . .
BTW, I posted again in the 144 vs. 250f thread . . .
From this page:
http://www.eric-gorr.com/services/cylrebuild.html
"YAMAHA
1993-2005 YZ80/100 (92-105cc) $400
1990-2005 YZ125/150 (133,139,144cc) $475
1990-2005 YZ/WR (265cc) $500
(Minor crankcase mods required for piston clearance on big bores for YZ105 and YZ150, send the whole engine and the mods are included in the prices listed above)
WHAT’S INCLUDED WITH CYLINDER REPLATING KITS
1)Your top end parts are carefully inspected to trace the cause of mechanical problems to save you money and recommend mechanical solutions.
2)The top end is disassembled and cleaned. A detailed work order is prepared noting mods needed to repair things like water leaks, faulty exhaust valves, broken bolts, casting flaws and cracks. Steel and aluminum parts are cleaned with different chemicals to prevent corrosion. Max Power charges you extra for each of these services and then hammers you with a hazardous waste charge of $15 and $25 for cleaning. I don’t charge extra and this work in included in the price of the package.
3)Next the metal machining process begins, including cylinder boring, porting, polishing, resurfacing of the top and bottom of the cylinder, cylinder head machining, and exhaust valve mods for the larger bore. You get to choose the powerband and type of fuel. This enables me to design the cylinder porting changes and head mods based on the fuel and if the bike is ridden at high altitude. RPM charges upwards of $300 and you don’t get a choice of powerbands. I only charge a maximum of $85 for more complete work. My specs are designed using recognized standards set by the Society of Automotive Engineers. I use TSR and Dynomation software to accomplish these design changes. For more information check out my Two-Stroke Technology page.
4)US Chrome handles all of my nickle-composite plating (NICOM) and diamond honing. USC has the best honing tooling in the business and an experienced German honing engineer that provides the roundest straightest cylinder bores for the best performance.
5)After the plating and honing is completed I chamfer all the ports and relieve the exhaust bridge using right angle porting tools and three grades of polishing media. Most of the competition relegates these tasks to the lowest paid laborers in their shops, yet it is one of the most important tasks because if its not done correctly it can lead to premature piston and ring wear.
6)The top surface of the cylinder is critical to head sealing. I machine an anti-detonation ring on the top of the cylinder, none of my competition does that! I also hand-lapp the top surface on a granite surface plate with polycrystalline media paper. Most of my competitors use things like sandpaper and glass, a hideous concept that is bone-chilling to real engineers and machinists!
7)Finally the top end is assembled with all the studs and exhaust valves and checked for proper operation. New COMETIC gaskets are included and the WISECO Pro-Lite piston kit is checked for fit and the ring gap is set.
8)Your top end is lubricated and sealed in a plastic bag ready for shipment.
9)Return shipping, I charge $10-20 for return shipping and when necessary I upgrade your package to UPS AIR to get it to you by Friday for no extra charge. My competitors use return shipping as a way to gouge you for things like insurance, packaging materials, and upgrades for air. Sometimes these additional “hidden” charges can total $75-$100 more that their advertised prices! "