07-07-15, 12:17 PM
I'm repeating myself but why don't you take them out yourself and clean them with some carb cleaner? If you've done any sort of basic maintenance you will be able to do it. It's not rocket science. There's no adjustment points that you can get wrong other than the idle mixture screws so you if you leave them as they are you can't do any harm having a go yourself. The worst case scenario is you damage a screw or jet and you have to get a second hand set of carbs which you're thinking about doing anyway. I can't see how valve clearances would cause a flat spot at a certain revs so I wouldn't worry about that. Have you got the basics right like air filter, spark plugs, leads and caps, throttle position sensor all good?