kawasaki scrambler. G4TR to Centurian

Alright so I picked up a little kawasaki off gumtree the other day (Aussie CL). The owner had it listed as kawasaki dirt bike, not running. So being a fan of a good bargain I borrowed the bosses ute and drove 2 hrs to pick it up.

when i got the bike home i put some new fuel in the tank and she started after 3 kicks! a bit smokey and wouldnt idle but it started. I soon realised that the clutch wouldn't engage also so I guess I was pullin the engine! I ran the Engine and frame numbers through google and I soon discovered that the frame is from a legendary G31M green streak! the 100cc 18hp flat track weapons that folks used to race before the 125 class came about. Although these things were infamous for destroying bottom ends hence the mismatch numbers. The engine is from a 1971 enduro the G4TR. These bikes had the same Rotary valve engine but detuned and with a Hi/ Low speed gear box (10 speeds!!) Luckily though the bike still had the Green Streak stinger pipe! so with a feew mods I may be able to get this thing from 10.5hp to around 18! mods include:
-Cleaning up Exhaust port as there are many casting imperfections.
-cutting the rotary disk valve to more of the G31M spec
-cutting the inlet port
-adapting a new carb, stock is a vm19 and the G31M ran a vm26

wow very cool I remember them they sounded like a banshee on crank(the piss to you guys)
if you give it the full mad spec it won't be much good for anything but wfo racing eh? izzat the plan some vintage racing ?

So I cleaned the carb, it looked like there was a couple of years worth of fuel in this old guy. with a new plug she starts first kick! awesome! I then rebuilt the clutch, the plates had formed one piece! they were completely stuck together. I managed to pry them apart and give them a soft rubdown with 400 grit sand paper and a soak in some fresh oil. After re-installation it rode great. although it has NO bottom end. it buzzes along quite well in the higher rpm's.

I plan on getting this bike road registered as it is pre 1974 i think it may be possible here in Aus but I am not certain. I will try though. I figured i would have a better chance of getting a Blue Slip (safety cert) if it looks nice so i went about cleaning and painting the engine. I have a little Soda blasting rig at home. I ended up making quite a mess.

I wont go FULL race spec but it would be nice to get it to around 16 hp. I plan on taking it to the local flat track where they have a vintage 125cc class. see if i can keep up. but also I live in the centre of Sydney so I mainly want it for terrorising the streets of Sydney!

awesome I may have a 24-26mm carby for that

Ohh really? That would be very useful! I sent you a pm about it. Cheers xb33bsa

Keen to see how this one turns out