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Drain the engine oil into a suitable container.
Loosen the clutch cable adjusting bolt, and unhook the cable end from the clutch arm on the side cover, then take the cable off the engine.
Remove kick start lever,
Remove the whole r/h side/clutch cover from engine carefully so you dont damage the gasket
Remove oil slinger if it has one fitted, remove clutch
Kick start gear's are the gear on the kick start shaft bottom left, idler gear is in the middle, drive gear is on the gearbox input shaft (fit's into back of clutch basket)
The 2x bigger gear's have a circlip holding them to the shaft
You will need a clutch nut tool (4 prong), some external circlip plier's, a 1/4 drive ratchet and socket's, 8mm, 10mm.
Replacement part's can be sourced from most pit bike shop's, or ebay if you are prepared to wait.
Electronics, Cars, Fashion, Collectibles, Coupons and More | eBay
TBolt USA: Pit Bikes, Engines, Parts, SSR, Pitster Pro, CRF5, KLX11
Double check the size of the shaft's that the gear's fit on to make sure you get the right size
16 kick start gears | eBay
yx gasket set | eBay