Monday 28 June 2010

Mixed fortunes at Magny-Cours

The RG 500 was running badly again, with a miss fire, and low on power at low revs. I changed the CDI which is really the last electrical component I haven't touched, and in timed practise, things started to come together, the bike worked fine at high revs, giving strong power between 8K and 11K. I had received my high volume radiator on the Thursday morning, before leaving and with this fitted the temperature never got above 84 degrees (a good investment!).

In timed practise I managed a 2:09 which put me middle of the grid on the 6th line.

As I lined up for the start of Race 1, I could hear the bike miss firing and blowing back through carb nr. 3, so I knew my problems were not over. I managed a couple of laps, but the problem got worse so I stopped! A brief session with the spanners confirmed that this can not possibly be an electrical issue - The fault was easily reproducible, and with a new plug, and swapping over the high tension leads, I could not get the problem to move - it definately has to be related to the carb or cylinder. Off with the carb, and no visible problems, so it must be an air leak somewhere.... The action plan is to look at the rotary valves (again), and potentially swap rotary disks between cylinders, and then if that doesn't work, I will have to assume leaky crankshaft seals, which will require a complete strip down and rebuild.

Luckily the RD 350 was running OK, although I had difficulty getting to the red line in 6th along the long straight to Adelaide. Everything was blasting past me on the straights, but I managed to have fun fighting with a group of guys, on am mixture or Ducati's, GSXR's, VFR's etc... so I was relatively pleased with the race. Magny-Cours is so fast, there are loads of places where on the 350 I didn't need to brake, and I am sure with more practise I could knock another 5 seconds of my lap time on the 350 - I could only manage 2mins 15secs. Anyway glad to have tried out the 350 with the new rad (swapped for a 4l0 radiator), which controlled the temperature nicely although, was pretty high, maybe unsurprisingly as the air temp was about 35 degrees centigrade.

Photos, and video to follow!

The extra power of the 500 (even running badly) was worth at least 6 secs per lap!

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