valves

So I have recently been experiencing problems with my motorcycle. General description: the bike bogs and backfires (out of the carburetor) when too much throttle is given within a short amount of time... My father and I have ruled out the carburetor, A/F mixture screw, plugs, plug wires...

Hey, everyone. It's about that time for me to replace the plugs, air filter and change the oil I suppose and it got me wondering...what other types of maintenance and small improvements can you recommend that greatly improve the performance and / or longevity of the bike? I'm all ears! Also...

Anybody ever come across an instructional DVD on how to adjust valves? There are a couple of mini home made ones on youtube that aren't that good. I did see a general motorcycle maintenance DVD for sale on Amazon, but it didn't cover valves. I'd really like to do my own, but I'd practice on a...