Big Bore Kits
Big Bore kits need to be installed by a qualified shop that's equiped for cylinder boring, sleeving and engine building to ensure that your kit gets installed properly, or we could install it for you. If you decide you would like us to do the build, then email us with any questions and for the current machining lead time at: joep@rpmmfg.com The prices shown are kit cost only and does not include Labor cost. The Installation labor prices are listed below.
Four Stroke Big Bore kits consist of: Sleeve, Piston kit, performance Cam(s) and Top end Gasket kit. Some kits may not have a sleeve if it's not needed for the larger bore.
Two Stroke Big Bore kits consist of: Sleeve, Piston kit, Top end Gasket kit and top pin bearing. Older big bore kits are still available for many bikes, inquire if you do not see yours listed.
KTM Two Stroke "Big Bore kit"
The KTM kits listed below, are Custom made by RPM Mfg and the prices include
Installation (Parts and Labor) Lead time is 6-8 weeks after your top end and payment is recieved. Our Big Bore kits are equiped with Wossner forged & coated pistons, LA Sleeve's and Cometic, Athena or Wiseco gasket kits. Send your complete top end only, Cylinder, head, piston & powervalve along with payment to the address listed on this website. If you don't see your model or year listed please inquire, we may be able to help you out.
KTM 200 to 220cc 1998-02 $635.00 - Inquire for lead time
KTM 300 to 330cc 1996-03 $690.00 - Inquire for lead time
KTM 360 to 390cc 1997-99 $690.00 - Inquire for lead time
KTM 380 to 410cc 1998-02 $690.00
This kit price is installed and free return shipping
410cc kits are in stock
(Crankcase clean-up required for 360 & 380 kits)
Limited stock Replacement Woosner 410cc kit pistons:
82.0mm Std. $197.00
82.5mm OS $197.00
Kawasaki Four Stroke
KX250F-262cc 2004-05 #LAS-5530
$625.00
KX250F-270cc 2004-05 #LAS-5530B
$685.00
KX250F-270cc 2006-07 #LAS-5611B
$685.00
Kawasaki Two Stroke
KX80-100cc 1986-00 #RPM-KX80
$240.00
KX85-107cc 2001-07 #LAS-5351B
$247.00
Check for availability on the following kits joep@rpmmfg.com
KX125-134cc 2004-05 #LAS-5570
$265.00
KDX200-240cc 1986-88 #RPM-DX200A
$350.00
KDX200-240cc 1989-94 #RPM-DX200B
$360.00
KDX200-240cc 1995-05
KDX220-240cc 1997-05 #LAS-5252B
$355.50
KX250-295cc 87-89,94,97-99 #RPM-KX250-
add your year after part # for correct kit
$360.00
KX250-295cc 2000 #LAS-5422B
$374.00
KX500 BIG BORE KITS BY RPM MFG & RACING SERVICES
and Oversize Pistons are in STOCK
KX500-540cc 1986-88 #RPM-KX500A
$475.00 - 86-88 Limited quanties available
KX500-540cc 1989-04 #RPM-KX500B
$475.00
KX500-550cc 1989-04 #RPM-KX500C
$525.00
Replacement big bore pistons are in stock
KX540cc 89mm # RPM8228D300 $198.00
KX550cc 90mm # RPM8228D400 $198.00
Honda Four Stroke
CRF250R-270cc 2005-07 #LAS-5597
$645.00
CRF450R-485cc 2004-07 #LAS-5537B1$545.00
XR250R-285cc 1996-04 #LAS-957B
$454.75
XR650R-680cc 2000-07 #LAS-5440
$460.00
Honda Two Stroke
CR80-105cc 1986-02 #RPM-CR80
$280.00
CR85-102cc 2003-04 #LAS-948B
$286.50
CR85-96cc 2005-07 #LAS-5599B
$265.00
Check for availability on the following kits joep@rpmmfg.com
CR125-139cc 2005-07 #LAS-5579
$292.00
CR250-295cc 1987-91 #RPM-CR250A
$325.00
CR250-270cc 2002-03 #LAS-5447-36
$325.00
Yamaha Four Stroke
YZ,WR250F-272cc 2004-07 #LAS-5536 $663.95
YZ426F-444cc 2000-02 #LAS-5424
$692.75
YZ450F-470cc 2006-07 #LAS-5627
$698.50
Yamaha Two Stroke
Check for availability on the following kits joep@rpmmfg.com
YZ125-134cc 1999-01 #RPM-5378
$288.00
YZ125-134cc 2002-04 (INQUIRE)
YZ125-144cc 2005-07 #LAS-5533B
$290.00
Suzuki two Stroke
RM85-100cc 2002-09 #RPM-RM85
$270.00
Check for availability on the following kits joep@rpmmfg.com
RM125-144cc 2004-09 #RPM-RM125
$310.00