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Monday, October 11, 2010

EVAP Removal Mod

The VFR1200F is equipped with an evaporative emissions control system. The purpose of this system is to comply with California Air Resources Board vehicle requirements. It draws fuel vapors from the fuel tank, stores them in a canister, and then purges them into the throttle body to be burned in engine combustion rather than evaporate into the atmosphere.

It's bulky and unneccessary so I took it out. My "green" European readers may find this offensive but this is a motorcycle blog, not a political blog so I'll avoid discussing the perceived environmental consequences here.

Here is the diagram for the system in the repair manual:

Here's what it looks like, located under the tank behind the rear cylinder head.

I joined the fuel tank breather hose to the evap drain hose, essentially bypassing the canister.

This is with the EVAP tray removed. Underneath the tray is a heat shield for the rear exhaust headers. The rear shock is also visible here.

I plugged the "purge solenoid valve to throttle valve" hose with a big bolt. This line goes to a manifold under the throttle body which splits it into 8 individual lines, 2 going into each intake port. To thoroughly remove the system, you could remove all the lines and insert vacuum plugs in the holes. It would be a lot more work and likewise a lot tougher to reverse if you had to.

The tray is reinstalled but with the solenoid and canister removed. I duct taped the solenoid plug and throttle hose to the tray so they won't rattle around.

This is what was removed. I threw it in a box of stuff I've removed from this bike... the box is starting to get heavy.

As was the case with the PAIR solenoid, the EVAP solenoid does not provide feedback to the ECU and therefore shouldn't cause a trouble code or malfunction light by being removed.


  1. How much does that thing weigh approx?

  2. not a lot... maybe 12 ounces

  3. What happens if you just disconnect the solenoid? I wonder if this is the cause for the stumbling and surging seen by a few VFR1200 riders... Bike starts up, solenoid dumps extra fuel into the system causing the bike to bog down, solenoid closes/gas fumes burned off, and the bike has a surge of power.

  4. Nothing happens if you disconnect the solenoid. This is an evaporative emissions system... it cannot introduce more or less fuel into the bike's fuel system. It simply cleans and purges the vapors.

  5. If the tonsils bother, take them out!!!!