Oil leak
Gasket, seal, and drain checks
This free guided diagnosis asks up to 4 questions about what the bike is actually doing and narrows it down to 7 possible faults, each with a safety call, what it costs to fix, and the guide that fixes it.
What causes oil leak?
Fork seal leak
Oil on fork tubes indicates worn seals. Replace seals and clean fork legs.
Do not ride. Fork oil runs down the leg onto the front rotor and tire. Do not ride until it is fixed and the brake is clean. Typical cost: $25-70 DIY, $200-450 at a shop.
Drain plug leak
Check crush washer and plug threads. Replace washer and ensure proper torque.
Ride with caution. Check the oil level before every ride and fix it now. Running an engine low on oil is how bearings die. Typical cost: $5-25 DIY, $60-140 at a shop.
Oil filter leak
Check filter O-ring and ensure correct installation/torque.
Ride with caution. Fix before your next ride. A filter that unseats can empty the sump in seconds at speed. Typical cost: $10-30 DIY, $60-150 at a shop.
Valve cover gasket leak
Common wear item. Replace gasket and ensure proper torque sequence.
Ride with caution. Not urgent for safety, but oil dripping onto a hot header or the rear tire is not something to leave. Typical cost: $20-80 DIY, $150-400 at a shop.
Engine case gasket leak
More involved repair. May require engine removal depending on location.
Ride with caution. Check the oil level before every ride. A slow seep can wait for a booking, an active drip cannot. Typical cost: $40-200 DIY, $400-1,400 at a shop.
General gasket leak
Identify exact location, clean area, and monitor to pinpoint source.
Ride with caution. Check the oil level before every ride until you have found the source. Typical cost: $15-120 DIY, $120-500 at a shop.
Shift shaft seal leak
Seal around shift lever shaft is worn. Usually replaceable without splitting cases.
Ride with caution. Fix it soon. Oil from the shift shaft lands near the countershaft and can reach the rear tire. Typical cost: $10-40 DIY, $100-260 at a shop.