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Big Bore Kits

TSP two stroke big bore

 

We offer Big Bore kits for most late model two stroke dirtbikes. These kits are a great way to bump up power and torque and often dont cost much more than a normal top end rebuild, especially if your stock plated cylinder is worn or damaged.

These big bore kits have proper porting and proper head designs to suit local fuels and conditions and as a result they offer MUCH better performance than most of the usual aftermarket big bore cylinder kits.

Send us your complete top end (old base gasket, cylinder, old head gasket, old piston, head) and we will bore, port and replate your cylinder, machine your powervalve to suit the new bore size, design and machine the head to give correct squish clearance and compression ratio and we’ll also supply a piston kit and top end gasket set.

When you receive the big bore kit it will be ready to install onto your bottom end and ride! Some kits may require carb and powervalve tuning to get the most of the new setup. Some kits require case mods. Please allow 2-4 weeks for return of your parts.

Final tuning will be the responsibility of the installer unless dyno tuning is requested.

 

Big bore kitFrom
Below 134cc (up to 52mm bore)$1399
134, 139 and 144cc (up to 58mm bore)$1500
265cc (68.5mm bore)$1600
295cc (72mm bore)$1650

 

 

Check out the following list to see what big bore kits we offer for your model…

Honda
ModelYearDisplacementSpecial Notes
CR80/851986-0792cc
CR801986-07100cc
CR852005-0792/100ccMust install oversized radiator
CR1251972-88134cc
CR1251989-04134cc
CR1251989-99144cc
CR1252005-07134cc
CR1252005-07139 or 144cc
CR2501978-80265cc
CR2501986-07265cc
Kawasaki
ModelYearDisplacementSpecial Notes
KX601983-200366cc
KX652000-1472cc
KX80/851988-201492cc
KX80/851988-2014100cc
KX80/85/1001988-2014107cc
KX1251985-1993134cc
KX1251994-2014144cc
KDX2001986-88212cc
KDX2001995-2006225cc
KX2501987-2007265cc
KX2501993-2007295cc
KX5001985-2001525cc
Suzuki
ModelYearDisplacementSpecial Notes
RM652003-0572cc
RM852002-1492ccCrankcase clearance mods needed
RM852002-14100ccCrankcase clearance mods needed
RM1251976-88134cc
RM1251989-2009144ccCrankcase clearance mods needed
RM2501989-2008265cc
RM2502003-08295cc
Yamaha
ModelYearDisplacementNotes
PW501990-1460cc
YZ80/851993-2014105ccCrankcase clearance mods needed
YZ1251976-89134cc
YZ1251990-93129cc
YZ1251994-2014134cc
YZ1251994-2014144ccCrankcase clearance mods needed
YZ2501979-89265cc
YZ2501990-2014265cc
YZ2501999-2014295cc
YZ/IT4651980-81478cc
YZ490/WR5001983-93510cc
Husqvarna
ModelYearDisplacementSpecial Notes
CR/WR1251998-2011144cc
CR2501998-2009265cc
CR2501998-2014295cc
Gas Gas
ModelYearDisplacementSpecial Notes
125 all models2000-2014144cc
250 all models2000-14265cc
KTM
ModelYearDisplacementSpecial Notes
50SX LC2001-0858cc
50SX2009-1458cc
65SX/XC1999-0872cc
65SX/XC2009-1472cc
105SX2004-14112cc
125SX/EXC2001134cc
125SX/EXC2001144cc
125SX/EXC2002-14144cc
150SX2007-14155cc
200EXC/MXC/XC-W1998-12212cc
250SX/EXC1996-05295cc
300EXC/MXC1991-14310cc
TM
ModelYearDisplacementSpecial Notes
1251998-2007144cc
2501998-2013265cc