BUY ONLINE WITH PAYPAL

There are a total of 3 different Wiseco forged pistons, and 3 different cast pistons from Athena and Vertex made to convert a 125 to an AMA ACU, AMCA, NMA, & FIM Legal 144cc engine. The Wiseco 830MO5800 is designed for the 2004-08 Suzuki RM125. The 846MO5800 is designed for the 2005-08 Yamaha YZ125. Eric Gorr’s Wiseco custom piston part number 9316MO5801 fits 7 brands of dirt bikes and nearly 100 models dating from 1989. Additionally Eric’s custom Wiseco fits bikes outfitted with a similar piston sold through Forward Motion and dealers since 1992, and Max Power/RPM since 1997. So if you have an old bike with a big bore, Eric’s piston probably fits it.

For customers looking for cast pistons, Italian piston manufacturers Athena and Vertex, make cast pistons to fit 58mm 144cc cylinders for the CR,KX,RM, & YZ. We’ll have an order box for them soon.

Free Evaluations of any sized big bore cylinders and pistons to provide part order numbers and original vendors, is available by sending the parts to:
Forward Motion Inc., 815 Walsh Rd, Unit 2, Madison, WI. 53714

Piston Trouble-Shooting Guide (PDF file link)
This is a color book reprint from the MX Performance book. If you are having problems with pistons look at this guide to help you fix engine and jetting problems.

HOW TO ORDER ONLINE
The kits listed below include complete top end gasket and piston kits. Piston kits include piston, pin, rings, and clips but not he bearing. Every order is sent by Priority Mail worldwide and travels within the continental US in 3 days with 5-day service to Europe and Canada. For Australasian countries, it takes 10 days. The freight for domestic orders is included and International orders pay an additional $5 per shipment.
When you click on the order icon for each item, it will open a Paypal form for you to complete. Remember to include the year make and model of your bike.

Supermini Piston & Gasket Kits

Honda CR80/85 1986-2006 766MO5200 $105
Suzuki RM85 2002-2006 806MO5200, 1013MO5300 $105
Yamaha YZ80/85 1993-2006 767MO5250 $105

Comprehensive listing for Eric Gorr’s Big Bore 144 Piston & Gaskets

Honda CR125 1989-1999, 2005-07 $125
Kawasaki KX125 1994-2008 $125
Suzuki RM125 1990-2003 $125
Yamaha YZ125 1994-2008 $125
GasGas 125 MX,XC 2000-2008 $125
Husqvarna CR/WR125 2000-2008 $125
IC Shifter Kart Engines; Vortex, Rotax, Pavesi, (piston kit only) $100

Wiseco 58mm Piston & Gasket Kits

Suzuki RM125 2004-08 836MO5800 $150
Yamaha YZ125 2005-08 846MO5800 $150

Big Bore 250 Piston and Gasket Kits in 265 and 275cc

Honda CR250 1986-91 265cc 614MO6850 $140
Honda CR250 1992-96 265, 614MO6850 $140
Honda CR250 1997-2001 265, 702MO6850 $140
Honda CR250 2002-04 265 801MO6850 $140
Honda CR250 2005-07 265 804MO6850 $155

Kawasaki KX250 1993-2003 265, 617MO6850 $140
Kawasaki KX500 1989-2001 525, 575MO8800 $150

Suzuki RM250 1990-95 265, 642MO6900 $140
Suzuki RM250 1996-98 265, 614MO6850 $140
Suzuki RM250 1999 265, 743MO6850 $140
Suzuki RM250 2000-02 265 756MO6850 $140
Suzuki RM250 2003-08 265 804MO6850 $155
Suzuki RM250 2003-08 275, 526MO6950 $140

Yamaha YZ250 1992-98 265, 677MO7000 $140
Yamaha YZ250 1999-2008 265, 804MO6850 $155
Yamaha YZ250 1999-2008 275, 526MO6950 $140

 

Call or email to order if you don't have a Paypal account and you want to use a Visa/Mastercard. Sorry no UPS C.O.D. or Discover/Amex

Telephone Orders Call 1-630-825-5645
Email: ericgorr@hotmail.com