I had one of the very first RZ50's in the country (i.e. the first batch that came in) That little thing was QUICK compared to the MT50 (still aircooled) I had before it (also my last non Yamaha motorbike ) It was fast (as a early 80's 50cc can be) up to its rev limit of 12000rpm (yes, it did rev up to that, no problem), but it worked out to an indicated top speed of just over 90km/h. Friend of mine's Dad owned the local Bike shop, and he worked there as an mechanic, so I used to visit him quite often. Scratching through a box of front sprockets one day, I found a 15t front sprocket (standard on the RZ was12t) that looked like it would fit. Checked, and yes it did fit. My buddy told me that with such a large jump in front teeth, I will not be able to get away, but I tried it in any case. I was greatly surprised to find that it got of the line with great ease, and the top speed jumped to an massive 120km'h indicated, at about 11000rpm. Back at the shop my buddy did not believe me, so when he took the bike he just finished servicing out for a test ride, I tagged along on the RZ, and sitting next to the bike he was on, he also recorded 120km/h. Of course I was over the moon with this, and started terrorising the local Delivery Gang on their 200cc delivery bikes. I was also the King of the Heap at the local Saturday morning dices. We then started playing with the bike, porting the hell out of it, and we fitted a Flat Slide Carb we found on a totalled 80cc MX bike. (can't even remember from what bike ) We cut the exhaust off just before and after the expansion chamber, and then the expansion chamber all along the weld and cut/re-arranged the baffle plates in the expansion chamber before welding it together again, this turned it into our homegrown performance pipe, while still keeping it looking stock. He also managed to source me a set of fibre reed valves, which transformed this bike into a real little monster. Somewhere along the line we also fitted a smaller rear sprocket, which increased the top speed considerably, but affected the acceleration a bit.(also can't remember what size sprocket, but it was a few teeth smaller) The piston was kept standard, we just "skirted" it a bit to make it lighter, and the conrod was also sanded smooth. We also decked the head a bit to up the compression ratio. All of this done with no scientific base, we just did what we thought might work, if it did, we kept it like that, if it did not, we returned it to standard if possible, or got another one, benefits of having access to parts. I did however spend a lot of time servicing my bike, "de coking" it, etc. I ruled the local dices, even against the later Kawa AR 50's and the few 80's that was around, the Honda MBX and the Suz Gamma's. Some of these were also heavily worked, but I weighed next to nothing then (under 60kg) so had a good power to weight ratio. I took it down Tarlton track, and ran a best quarter mile of 21sec at 116km/h (dropped a friend in his new Ford XR3 that day) Sitting upright in the right conditions, I could maintain 120km'h, crouching took the top speed up to between 130-140km/h and slipstreaming was a tad shy of 160km/h At the Hillsnacks dices in Krugersdorp, I also ruled the roost, only being beaten by a track orientated 80cc Honda that was geared so tall, it had to be pushed off the line to get going. Kept that little bike for many years, even after I had an RD125LC and my first 350LC. Still took it out to the dices every so often, just to piss the youngsters off. Eventually sold it to a friends younger brother. Ah, those were the days. For some or other reason, these are the only photo's I have of any of the bikes I owned over the years. I know I have a photo or two of my Eleven Special somewhere, but can't find it.
