So, I took the cylinder off the RG500 at the weekend, to look at the damage from my seize. Not too much damage and nothing above the rings, so a little TLC with some fine emery cloth, on the piston and the cylinder, and she is as good as new (almost). I also took the needles up 2 grooves, so I am running them one above the lowest groove. I am hoping this should improve my carburation hole at around 6K rpm. From reading various articles on carb tuning it would seem that I may be running lean at partial throttle - I will try this out tomorrow (up and down the road!). Apparently lean mid-throttle jetting can be characterized by a lack of power (hole), and a loud induction sound (wouououououou) noise, which fits pretty much what I was perceiving. Hmmm technical stuff.....
Annyway had troubles with one of the needle screws as it was completely solid and the top had been mullered by the previous owner, so I had to get the drill out, and drill down the throttle slide (5 cm hole) into the screw head. I actually managed a pretty straight line hole going out the other end of the throttle slide, to which I added a new thread and found a screw that would fit, so it all ended happily.
Other work at the weekend was fitting a new radiator to the RD 350, I learnt from a guy at Nogaro that the 4l0 (an earlier model 350) has a larger double core rad, so I ordered a second hand one from RDLCCRAZY, and received it during the week. It took me a couple of hours to make some brackets to hold it, and I am realtively pleased with the results. Hopefully the 350 at least will run cooler at Magny Cours. The only issue I had was the original water circuit has a thermostat bypass pipe that allow water back into the top of the original rad. this was not present on the new rad, so I have removed the thermostat allowing full water circulation the whole time, and I have closed up the bypass pipe with a bolt screwed into the rubber pipe (I hope it holds...).
Little left to do now except decide on initial gearing for Magny Cours (I'll go with 15/39 to start with), and await my high capacity radiator for the 500, hopefully it will arrive before race weekend.
Speak to you soon.