Mini Bike Jack Shaft Systems, Performance Engines, Adjustable Motor Mounts
Mini Bike Performance Exhaust Headers, Honda GX200 and Clone Engine Performance Parts 
Baja Doodlebug and Motovox Minibike Engine Swap Kits

Click Banner to enter new WebStore!

Baja and Motovox Mini Bike performance Parts Specialist 

ProMod Jackshaft Kit


 Click to view Online Store

Fix your poor performing Baja or MotoVox Mini Bike!

The PMR bolt on Jackshaft Kit is an easy to install performance upgrade for
the Baja Motorsports Mini bikes, Motovox MBX10 Mini Bikes 
and other Kart and Mini Bike projects.
Sturdy lightweight CNC Aluminum construction with double bearing housing.

DirtBug and DoodleBug and Motovox Mini Bikes suffer badly from
not having a gear reduction system .
 Installing this kit and adjusting the throttle stop screw will result in surprising
performance gains. Great mod for kids and adults alike.

Watch Video!    Click

Complete Kit for stock 97cc engine comes with with chain,
hardware and directions supplied for a bolt on
installation retaining all factory chain safety guards


Fits New or Original style DB stock 97cc 2.8hp engine
and Motovox MBX10/11
Original model has metal fenders  and straight top frame rails

Jack shaft
Kit for Original style Baja
Doodlebug,Dirtbug,Racer ,Blitz and Rivet

Jack Shaft Kit for New Model Doodlebug

New model has plastic fenders and bend in top frame rails
New Style  DB30R JS Kit

Jack shaft
Kit for new
Motovox Mini Bikes

Motovox MBX10 and 11 Kit


PMR Performance Jackshaft for 4-6.5hp engine's
 Easy gear ratio adjustments
Shown with 13t-15t combo. Input and output Sprockets  which can be
easily switched from high torque 6.73-1 ratio to high speed 5.03 -1 ratio.
Jackshaft plate bolts to most any engine with the standard 2.5 inch
engine PTO side cover bolt spacing.
This system has been tested on Karts and highly modified engines with 15- 20+ HP  !
Optional custom gearing available at your request!          


Supplied with Jackplate assembly ,Clutch spacer and mounting hardware 
Note! Chains not included
Jackshaft system can also be used with PMR Clutch Cover.


 10ft #35 Chain


#35 Master Links

#35 Master links

Click here for
Jack shaft replacement Parts


 PMR Clutch and Chain Cover



Laser cut and tig welded Aluminum Cover 
offers great protection from chain or clutch failure.

 Covers supplied with adjustable mount system using 
 quick release Dzus fasteners and hardware.

 This cover can also be used with performance disc style racing clutches.
Note# spacing out the mount with a few washers may be required with certain disc clutches.




Baja  Warrior, Heat ,MB165 -200
Mini Bike replacement Jackshaft

Quailty JS system to replace problematic factory system

Can be ordered with optional #35 chain primary   
for a smoother operation with less drag and chain noise
#35 chain clutch required for this option

PMR clutch cover also works great with this JS System !

Jackshaft Kit for  Baja Heat and Warrior 
MB165  and 200 Mini Bikes.
Complete with mounting hardware
 Note! Chain not included
MB165-200 #40-41  17t Primary and 10t output sprockets

Optional upgrade with #35 20t Primary sprocket  and #41 10t output for MB165-200
  12t #35 3/4 clutch recomended for this application

Website Builder