In karting the driver is only half the story: a slipping clutch, a wheel that turns stiffly or a dry chain costs tenths of a second every lap. A kart needs regular, careful servicing rather than repairs once something has already failed.
Below is a basic routine between sessions: the clutch and its needle bearing, wheel bearings, chain, electrics and general protection of the metal against moisture, dust and grit thrown up from the track.
What you will need
Important: Work on a cold engine with the spark plug lead disconnected. Keep all lubricants off the brake disc, pads and tyres, and wipe them clean if any overspray lands there.
Step 1
Strip the clutch
Put on gloves. Remove the chain and take off the clutch drum: undo the cover screws, remove the part underneath and you will see a washer and the needle bearing.
Take a photo of the parts in order so you can reassemble them correctly.
Step 2
Clean and lubricate the needle bearing
Wipe the area where the parts came from with a dry cloth. Use the straw of WD-40 Smart Straw to flush old dirt from the bearing and clutch drum, then wipe dry.
Apply a thin coat of WD-40 Specialist White Lithium Grease to the needle bearing: it stays put while spinning and does not wash out. Keep the clutch shoes dry. Reassemble in reverse order.
Step 3
Check the wheel bearings
Lift the kart onto a stand and spin each wheel by hand. It should turn freely with no grinding or play.
Aim the same can's straw at the inside of the hub and turn the wheel while spraying so it spreads evenly. It drives out moisture after a wet session. Replace any bearing that still grinds.
Step 4
Service the chain
Wipe the chain with a cloth dampened with the same spray to remove sand and old grime. Let it dry.
Apply WD-40 Specialist Roller Chain Lube to the inner side of the chain while slowly turning the rear wheel. Give it a few minutes to set, then check the chain tension.
Step 5
Clean the electrics
Treat the kill switch connector, sensor wiring and battery terminals (if fitted) with WD-40 Specialist Contact Cleaner. It evaporates quickly, leaves no residue and dissolves dirt and oxidation.
Reconnect only once everything is fully dry.
Step 6
Protect the chassis and metalwork
Apply WD-40 Smart Straw to the front of the kart, brackets, steering rods and pedals, then go over them straight away with a dry cloth. The thin film reduces friction in the joints and protects against rust.
If you look after several karts, WD-40 5 l with sprayer is more convenient.
Tip: After a wet session treat all joints and bearings the same day: water and sand start attacking the metal overnight, and by the next weekend the steering rods can already feel stiff.
What next
Check the chain and wheels before every session and service the clutch every few race days. Before winter storage, treat all metal parts the same way.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».