well there wasn't too many helpful comments on here before i set off - but i went anyway and bought myself a great condition 10k miler c2. it was a 240 mile ride home and the bike developed some rough running at around the 2.5-3.5k rev area which slowly expanded as the journey wore on. i'll have to have it looked at - but any ideas?
As far as the roughness is concerned, carb icing or gummed up carbs could be a factor. The carb heater has a small inline filter that needs to be kept clean but icing will only be an issue when the weather is fairly cold & the air damp. The other possibility is if the bike has been stood a long time then evaporating petrol can leave a gummy residue in the carbs, for which they would need stripping & cleaning.
Saying that it may just be a case of giving the bike a good service. Smooth & well lubed controls will give a good indication of how well the service items have really been dealt with. Check air & fuel filters anyway.
thanks shortcircuit. it has all the history you describe - been stood unused since april and last night from cornwall to hampshire was fairly damp! this morning and afternoon however it ran very smoothly indeed - and pulls like a train! i figure it just neede the run and a damn good clear out. after my 4 hour cleaning session it looks very smart too!
As the bike's been stood up worth getting some STP fuel additive, can't remember what it's called but it cleans out the carbs of any fuel residue & may help improve running. Put half a can in each fill up, comes well recommended.
gearbox, gearbox, gearbox but if thats ok you should be fine. take it for a good spin and go up and down the box making sure it goes into all gears smoothly and doesnt jump out of any gears. if it does walk away your looking at a lot of money to fix