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KLR650 Thermostat Bypass Installation Instructions

Submitted by Lora B on

(See available PDF for printable version)

  1. Remove seat and fuel tank.
  2. Drain the coolant.
  3. Remove the 3 bolts securing thermostat.
  4. Remove original thermostat and set aside.

  5. Install brass elbow into bypass housing using Use Teflon tape or thread sealing compound. Elbow should point forward from top of housing as shown in diagram below.

  6. Install O-ring into original thermostat pocket on the cylinder head.
  7. Install new thermostat into bypass housing making sure the thermostat body does not block flow into the brass elbow.
  8. Using the longer stainless-steel bolts, install the bypass housing, thermostat, and thermostat housing on to the cylinder head.
  9. Cut the lower radiator hose about 3” from the radiator connection directly behind the frame down tube.
  10. Install the tee fitting between the 2 halves of the lower hose and use the 2 larger hose clamps supplied in the kit.
  11. Install the supplied bypass hose from the elbow to the tee fitting using the 2 smaller supplied hose clamps.
  12. Refill coolant system with coolant.
  13. Run engine until warm, then allow to cool and top up coolant level in radiator.