Although Timburr does have a low base 35 Speed it is quite hard to revenge kill with its massive attack stat and access to priority Mach Punch. However if you can predict when a Timburr is going to swith in a Murkrow and Abra can do quite well with their Brave Bird and Psychic respectively. As for Pokemon that can wall Timburr a lot of bulky poison-types can do a good job because they resist Timburr's Fighting-type stab. Unfortunatly there is not too much of these Pokemon available. Woodchuck did mention Foongus who has Clear Smog to remove Timburr's stat boosts and can put him to sleep with Spore. Koffing is another bulky pokemon that resists Drain Punch and Mach Punch and can use Clear Smog to get rid of Timburr's Bulk Up boosts. Croagunk with its fantastic typing resists the standard Timburr's Dark/Fighting coverage and can hit it on its pitiful special defense with Shadow Ball or Vacuum Wave. The latter is a Stab move that has priority thus being faster then Timburrs Mach Punch.