The most economical and effective way to increase the performance of your engine. Available for two stroke and  four stroke KTM Motorcycles a like. Whether racing or just trail riding, increasing your engine displacement with a big bore kit will give you that added power you've been searching for. Big bore kits are very reliable and easy to install when compared to most other engine modifications.

Here's what Motocross Action Magazine said about it "Big boost: Dollar for dollar the most efficient way to get more power out of a four stroke is to increase the displacement. "The KTM280 Big Bore Kit "...kit is inexpensive and powerful" KTM 250 Big Bore Kit "...makes it easier to get off the line and more adept at handling hills, sand and mud. " KTM 250 Big Bore Kit  "...pulls like a John Deere to the first turn, there is nothing like three more horses focused on one job." Motocross Action

What does it cost? Would you believe $489.00. That's it and all you have to do is button it up and check your carb jetting.

Send us your cylinder (and head, along with the power valves/two stroke cylinders only), we will bore, sleeve or Re-Nikasil your cylinder to the new larger size. Your power valves will be modified if needed to function properly with the larger bore size. Some models will have the cylinder head re-chambered for the proper volume and compression ratio. Our big bore kits include a high performance piston with piston rings, piston pin and circlips. New top end gaskets are included for most models.



We highly recommend using the Crower Power Cam -Victory Series.
Developed to give your engine more power in the mid-range area of the power band.The Victory cam is recommended for use on outdoor style motocross applications.This camshaft works equally well for recreational off-road riders. Everyone from fast novice riders to some of the fastest pro's can benefit from it's design and performance

Call for price 888 697 4343


We also recommend the Dr. D Exhaust to complete the package.


$ 489.00
All you have to do is send us your cylinder (can be ...
$ 476.00
Your cylinder will be bored and Re-Nikasil coated to...
$ 504.00
All you have to do is send us your cylinder (can be ...
$ 615.00