UTV runs rough after a water crossing: airbox and CVT drains

Applies to: Yamaha Wolverine RMAX and most sport and utility UTVs

Symptoms

  • Coughs, misfires or won't rev after deep water
  • Belt slips after the crossing
  • Water or milky oil in the airbox

Why it happens

Water gets into the airbox and the CVT case. A wet air filter chokes the engine and a wet belt slips. In the worst case water reaches the cylinder.

How to fix it

  1. Stop the engine right away; don't keep cranking if it won't turn over.
  2. Open the airbox and CVT drains and empty the water.
  3. Dry or replace the air filter.
  4. If the engine won't turn, pull the plugs and crank to clear water, then change the oil if it looks milky.
  5. Dry the belt by running in neutral per the manual.

Tools and parts

  • Air filter
  • Spark plug socket
  • Engine oil and filter

What the factory service manual covers

Air intake, CVT drain locations, oil change and spark plug service. The full procedure, specs and wiring diagrams are in the factory service manual for your machine.

Get the factory service manual

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