How to care for your dirt bike
These top tips will have your off-roader running sweetly
1 Block off your bits
A pressure washer is the only way to clean a well-used dirt bike, but you need to make sure water doesn’t get in the wrong places. Invest in exhaust bungs to stop water going back up the pipe and into the engine, as well an airbox cover to prevent water contamination in the carburettor. Don’t have these items? Folded cloth sealed with gaffa tape can work just as well.
3 Beat the thieves
Off-road bikes have always been prone to theft, so as well as taking the usual precaution of keeping your bike chained up in your garage you should also fit a tracker. The latest GPS tracking units, such as the one in the picture, can be bought for as little as £30 and require no hard wiring so can be easily hidden.
2 Breathe freely
Clear the air filter regularly. The engines in these bikes are tuned to make power at high rpm and this demands a lot of oxygen. The air is scrubbed by a foam type filter that has oil in it to help remove small dust particles. If it isn’t cleaned regularly the airflow will be reduced and the engine will run rich, affecting performance.
4 Chain care
Keep the chain adjusted to the tension detailed in the owners’ manual. Too loose and the chain could jump the sprocket, too tight and it could bind the suspension. Never assume that chain tension is consistent from one model to another, as often it’s wildly different. Never forget to lube the chain when you have finished cleaning the bike.
5 Spokey dokey
Wheels need to be routinely checked for loose, buckled or broken spokes. You should inspect the spokes individually and also make sure the rim itself is not buckled. Tighten the spokes with a spoke wrench or use a proper spoke torque wrench to prevent overtightening.
7 Check coolant
Having the correct coolant level is especially important on competition four-stroke bikes which tend to run very hot. In milder conditions use de-ionised water; for winter storage and colder events mix deionised water with a concentrated antifreeze. Always make sure that any rad guards are clear of mud and that the radiator itself is cleaned often.
9 Have a look at your hub
Most off-road bikes don’t have a cush drive assembly, the sprocket is mounted directly on to the rear wheel hub to give the rider the ultimate connection to the back wheel and feel for the terrain. The downside is that the sprocket mounts need to be checked regularly. Check each one in turn and torque up to spec. Also check for damage or wear to the sprocket itself.
6 Bleed your forks
Off-road forks have a tendency to take in small amounts of air past the seals which over time can change the handling as the forks slowly pressurise. This will eventually blow the fork seals. Check the owner’s manual for the location of the air bleed screw on top of the fork leg.
8 Check critical bolts
Regularly check any fastenings, such as the fork yoke clamps, that have their specific torque values highlighted in the owner’s manual. Using the correct torque here is so critical that the precise value is embossed on the yoke. This KTM requires only 12Nm per bolt, that’s probably half what most people would think it should be.
10 Inspect your rubber
Examine the tyres regularly to check for cuts on sidewalls and missing tread blocks. Off-road bikes are subject to much more abuse than road bikes. The edges of rocks and debris on some terrain takes its toll on tyres. Rocks can easily tear off the tread blocks of knobbly tyres, while harsh impacts can damage the sidewalls.