Intro:
Both the cooling system and the gearbox oil will need to be drained to complete the install of the big bore kit.  If you are not replacing the clutch, then you will not have to drain the gearbox oil.  Warning, you must replace the clutch with a Barnett clutch kit, if you are actually going to ride your big bore bike aggressively at all.  The stock clutch can be smoked in one afternoon and a Barnett can last a very long time.  We like to drain the coolant first and the gearbox oil second. 

Draining the coolant:
To drain the coolant, you first remove the filler cap on the left side dash panel, and then remove the drain bolt on the water pump (see picture 1).  This is the only bolt on the water pump that has a sealing gasket on it.  Blue coolant will now start running all over the place if you don’t have a good sized catch pan in place.  Let the coolant drain for a minute or two to ensure that most of the coolant is gone from the system. 

Draining the gearbox:
Now remove the gearbox oil drain bolt from underneath the motor and let it drain for at least 5 minutes to get it all out.  This is a 13mm gold colored bolt (see picture 2).  Now that the fluids are out of the motor, the fun part can get underway.

Refilling the coolant:
After the big-bore conversion is done, you need to refill the coolant system.  First, ensure all hose clamps are secure, and then replace the coolant drain screw.  Fill through the reservoir cap located on the left side top fairing.  Now grab different coolant hoses and squeeze them by hand.  This will help get rid of any air trapped in the bends and on the walls of the rubber coolant hoses.  The level will go down again.  Repeat process until level stays constant.  If you are starting the motor immediately after these steps, make sure to check the level again after it has run for a couple of minutes and again after the first ride.  For racers only, use straight distilled water and a Water Wetter-type product.  For street use, we recommend a 50/ 50 mix of distilled water and phosphate-free coolant.  For extremely hot climates, a 75% water and 25% coolant mix will carry away more heat. Warning: For those running straight water, remember to drain it before the winter.  Freezing water can and will crack crankcases (think $$$$).

Refilling the gearbox:
Once the Barnett clutch conversion is done, you must refill the gearbox with 75W90 full synthetic gearbox oil.  First, remove the oil level screw in the middle of the side cover.  It is a Phillips headed screw (see picture 3).  Also, remove the fill plug.  Replace the oil drain plug.  Begin filling the gearbox.  Stop when you see oil drip out of the level screw.  With the bike completely level and upright, let all the excess oil drain out.  Replace level screw and fill plug.  DO NOT OVERFILL THE GEARBOX.

Proceed to Step 3: Airbox, Carburetor, Manifold, and Reed Cage Removal

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