Have to say I like to see the results, if for no other reason than to see how bad I really am against the others. Kinda lucky though cause both the clubs I'm in have the results up quick.
Start unbolting the tank/Mud guard etc, it should all pull apart easily enough I'd have thought. Clean fuel tank out, new fuel, clean carb, new plug etc.....it's how I would start anyway
Hope it goes well for ye, looks a nice oldie
Only the very early models had issues, and they were all sorted under warranty.
My 290 is smoother than a smooth thing winning first prize in a being smooth competition, so don't believe everything you read, especially on internet forums.