Used Bike Guide – Motocross Bikes

Filed under: Buyers Guide |
  • Look for cracks and dents on the frame, near the engine mounts. These can get cracked on bikes that have experienced a lot of hard landings.
  • Pay particular attention to bearings (wheel bearings, swingarm bearings, steering head bearings) – dirt riding and frequent post-dirt pressure-washing are a bearing’s worst nightmare. Check them for notchiness, looseness, etc.
  • Many dirt bikes will have been raced in local motocross races, so while the standard caveat about bikes that have been raced still applies, you may have more trouble finding a bike that has led an easy life.
  • Particularly with smaller dirt bikes, you should ask the seller who the main rider has been – adults tend to be more gentle with bikes than kids.
  • Ask the seller where the bike was ridden – sandy/dusty areas may cause more wear on chains/sprockets/bearings and will require more frequent air-filter cleanings than an equivalent amount of time spent riding trails.
  • It’s usually easy to remove the flywheel cover on two-stroke dirt bikes (typically on the left side on recent models) – the rubber gasket won’t be damaged by removing the cover. Pull the cover off and, grabbing the flywheel, try to move it off its axis. If you can feel movement, either the flywheel is loose, or the crankshaft bearings are badly worn. In other words, you may just need to tighten the flywheel mounting bolt(s), or you may need to have the cases split and have the lower end bearings replaced. (£40-£70 of parts a couple of hours  of labour.)
  • If you take this flywheel cover off and  see oil dribbling out, the crank seal has failed and the engine will need to be disassembled to fix it. (£30 or so of parts and a couple of hours of labour.)