Junior Gearbox 140


JP140 class

Any Pitbike fitted with a maximum wheel size of 12"

Fitted with either a Lifan 140 / YX 140 /  z140 engines


Engines must be completely standard with maximum 26mm carb,

No Porting

No Milling

No Polishing

Standard Gaskets

Standard Cams

any Tyres

Maximum 12" Wheels


Must be fitted with drilled & lockwired sump plug, wrap around reinforced hand guards, axle bobbins, foot peg sliders and a netal 1,5ltr catch tray


Maximum BHP output on NMRRC Dyno=<

(will be set after testing during feb - but a truely STANDARD yx 140 / Lifan 140 will be within the limit set)

Junior Gearbox


Mini GP UK


Please see the mini gp uk website for further information.











This class is for riders between the age of 9 & 14 years old.

It is designed to keep costs to a minimum with all eligable machines fitted with standard 140cc engines . The rider can choose to race either a minigp or ptibike style machine.


This allows the budding racer to hone their racing skills in a extremely competitive class, the restriction to standard engines places the emphasis on rider skill rather than the size of their parents cheque book.


At this stage the entry levels mean all machines will race together but will score seperate points and  be allocated as the following classes


Metrakit GP 50

Metrakit GP 70 

Mini GP / Pitbike 140

Metrakit GP50 / GP70


Eligible Machines:

“As supplied” MetraKit MiniGP50 motorcycles fitted with the following motors: Minarelli AM-6, Derbi Senda / GPR, or the

Metrakit 50cc O.E motor as introduced in 2009. Motors must remain un-modified from manufacturers original supply


1) The gearbox oil drain must be drilled and lock wired.

2) Catch bottles must be  on all gearbox breather pipe, fuel tank breather pipe and radiator overflow pipe.

4) Clearly visible allocated race numbers to be applied to front of fairing and either side of the fairing or seat tail.

5) Open tyres

6) Footrests must be changed to nylon material or have good condition nylon / plastic end caps.

7) Handle bar ends must be nylon capped

8) Wheel Spindles must be capped with nylon bobbins or swing arm and fork ends drilled and bobbins attatched.