So you want to increase the overall performance of your engine? For that, there’s one thing you need and that’s displacement. Nothing else is as important, since the boost in displacement is tied to your torque performance. And for that, you need big bore kits.

For other engine modifications, you’re usually forced to choose which end of the power band to sacrifice so you can enjoy an improvement in the power on the end. This time it’s different when you have a suitable big bore kit. You won’t find any other type of modification which can give you the improvement in performance that you can get on the Kustom Kraft big bore kit.

Now you get an increase in both horsepower and torque, and that’s over a broad range. These big bore kits are utterly reliable, and for great low end you get a huge boost in torque. And at the same time, the power is also enhanced all through the whole power band.

The Benefits of Kustom Kraft Big Bore Kits

You will find that the benefits you get from our big bore kits are utterly tremendous:

  • As we’ve said, you get a boost for both horsepower and torque, and throughout the entire power band.
  • This is the most effective way to boost the engine performance.
  • It’s also among the most affordable ways to boost engine performance, as many other modifications are much more expensive.
  • This improvement is available for 2-stroke and 4-stroke motorcycles, and for ATVs. You’ll get the additional power you need, whether for just trail riding or for serious racing.
  • Kustom Kraft has big bore kits for all the popular brands.
  • All you need to do is to send Kustom Kraft the cylinder and head plus the power valves.
  • Kustom Kraft will do the rest, including boring, sleeving, or replating the cylinder to the new size. Modifications will be made to the power valves, should they be necessary for the valves to work properly with the bigger bore size. In some cases, the cylinder head will have to be re-chambered to the right volume and compression ratio.
  • If your cylinder is fried, then you really don’t have much of a choice except a big bore kit.
  • Most of the time, it’s all a matter of bolting the kit on and then tuning the carburetor. After the beak-in, you’re good to go.
All you need to do is to determine the big bore kit you need. Detach the cylinder from the motorcycle, and then remove every component from the cylinder that’s not really necessary for modification. Carefully pack it, and then send the package to us. We’ll do the rest. We do have a wide range of big bore kits, including for 2-stroke off road motorcycles, 4-stroke off road motorcycles, 2-stroke ATVs, and 4-stroke ATVs.

Honda Big Bore Kits
This is of course a well-known brand, so its big bore kits are much in demand. The big bore kits are for numerous models.

  • For the 2-stroke off road, prices range from $329 (CR 80 1986-2002 90cc) to $495 (CR 250 1986-1991 310cc).
  • For the 4-stroke models, prices range from $229 (CRF 150 2003-2005 170cc) to $549 (XR 650L 1993-2006 720cc).
  • For the 2-stroke ATVs, it ranges from $329 (TRX 250R 1981-1984 270cc) to $495 (ATC 250R 1981-1984 290cc).
  • For the 4-stroke ATVs, it ranges from $379 (TRX 400EX 1999-2004 440) to $479 (both for the Fourtrax 350 1986-1989 452 and the ATC 350X 1985-1986 452).
Kawasaki Big Bore Kits
With these big bore kits, you get 30% more displacement and 30% more torque. Most of the horsepower boost is in the lower RPMs.

  • For the 2-stroke off road, prices range from $369 (KX 65 2000-2006 71cc) to $629 (KX 500 1986-2004 560cc).
  • For the 4-stroke off road models, prices range from $279 (KLX 110 2002-2006 130cc) $849 (KLX 250S 2006-2015 330cc).
  • For the 2-stroke ATVs, it’ll cost $450 for all the year models of the KXF 250 310 and the KXT 250 290cc.
  • For the 4-stroke ATVs, it ranges from $540 (KXF 400 2003-2006 440cc) to $749 (for several different models).
About the same price ranges for the motorcycle big bore kits and the ATV big bore kits can be found for the Suzuki and the Yamaha models. We also have KTM Big Bore Kits, including the KTM 280, the KTM 250SXF (for the 280cc and the 265cc), and the Crower Power Cam -Victory Series camshafts. What more do you need? If you need more performance, send us your cylinders and we’ll put in the big bore kits you need.

Suzuki Big Bore Kits

Yamaha Big Bore Kits