LAST DANCE FOR ERIC GORR
 
2023 is the last year I will produce PORTED big bore kits with my own two hands.
I will continue to sell and market my custom pistons and gaskets and manufactured cylinders.
 
Starting January 1, 2023 you need to call or text for an appointment because I have limited space
in my workshop. No more sending engines without paperwork or a clear ability to pay for the work.
Text or call Eric Gorr for a time estimate and appointment (630) 825-5645

Big Bore Master List

COMPLETE KITS PARTS AND LABOR

 
BigBoreKits
 

3 CHOICES - SUPER-STOCK, SUPER-MOD, AND BIG BORE

All kits for original plated cylinders include new piston kit, top end gaskets, copper washers and alignment pins, top end bearing for parts. 
The repair services include clean & chemical strip, TIG welding, boring, NICOM plating by USC Technologies, cylinder head resurfacing and 
mods, cylinder base machining, and powervalve cleaning and assembly. THERE ARE NO EXTRA CHARGES. We won't nickel and dime you 
with silly charges like stud removal, hazardous waste disposal, shop supplies like our competitors do. The following are special options for 
each kit.
 

SUPER-STOCK (SS)

These kit are for riders whom want to keep their cylinder the original size to be legal for stock classes in any racing organizations. We push 
the edge of the envelope by Blue-Printing the ports to the same timing as quoted in the Factory Service Manual. Also the gasket surfaces of 
the cylinder base and head will be turned on a lathe and the head chamber polished. For bikes with powervalves we will clean and polish the 
parts and re-time the parts for easy installation. You get the added choice of setting the cylinder head to run pump or race gasket and to 
compensate for high altitude riding. Piston choices include Wiseco, Pro-X, Vertex, and Wossner.
 

SUPER-MOD (SM)

These kits feature a maximum oversized bore (2mm/.080inch) for displacement/modified classes. Also included is cylinder porting and 
polishing with head mods for 3 choices of powerband and fuel types: #1 More low to mid-range #2 More mid to top end #3 More better 
wider power and the fuel types of 91 unleaded pump gas, 98+ race gas, and oxygenated race gas.
 

BIG BORE  (BB)

These kits feature the biggest bore size (4-6mm/.160-.240inch) vet/displacement/modified classes or outlaw racing. Also included is cylinder 
porting and polishing with head mods for 3 choices of powerband and fuel types: #1 More low to mid-range #2 More mid to top end #3 
More better wider power and the fuel types of 91 unleaded pump gas, 98+ race gas, and oxygenated race gas.

JAPANESE DIRT BIKES and ATV

EUROPEAN DIRT BIKES and KARTS

We also have kits for ATK, GasGas, Maico, TM, and Zundapp based on piston availability.