TB KLX140 Big Bore Kit, Mikuni VM26, & Carb Kit – All KLX140s

TB Parts 170cc Bore Kit with the our Mikuni VM26 performance carb kit. These parts work great together for an unmatched performance increase. Starting with the complete big bore kit you get a lightweight high compression piston that is 5mm over stock making close to 50% more power. Add the 6mm larger VM26 carburetor (that utilizes the stock air box) and the bike will not only start up and idle better but it also feeds the engine more air and fuel to make more power through the entire powerband. This is one of the best, if not the best kit you can run on your KLX140 to reliably wake it up without breaking the bank. Also using the stock camshaft keeps this engines smooth running characteristics that are great for trails! We stock replacements for everything in this kit and jets for the carb. Not to mention we are continuing to grow our performance and replacement KLX140 parts lineup!

Kit features:

• Huge power gains at the best price!
• Aluminum cylinder with steel sleeve (63mm)
• High compression 63mm piston with rings, pin, & clips (Safe on 91+ Octane Pump Fuel) (Note: The arrow on the piston marks the intake exhaust flow/valve relief)
• Top end gasket kit
• Genuine Mikuni VM26mm Performance Carb (Not a cheap Chinese copy carb)
• Intake Kit port matched to the VM26 and stock cylinder head
• Main Jet kit (Stock Main Jet size is a #190 – Extra jets sizes 140, 145, 150, 155, 160, 165, 170, 175, 180, & 185.)
• Extended Throttle Cable for use with the stock bars and throttle or tall bars.

Note: 2025+ KLX140s – require case boring to fit. The TB cylinder skirt is 65.95mm 2025+ cases are only 65.4mm wide.

For 2024 and older models: This kit does not require boring of the case – simply bolt on and go!

There are no installation instructions, but if you can replace your piston, you can install this kit. If you don’t have any experience working on your engine, we highly recommend having a professional technician install this kit or, at a minimum, purchasing the shop manual for your bike available from your local Kawasaki dealer. The parts are installed in the same manner as the OEM parts.

Installation note – KLX140 camshaft bolts are reverse threaded, turn them right/clockwise to loosen/remove. A good jet starting point is the factory #22.5 Pilot and #180 main with the stock pipe.