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Note:  Mechanical aptitude and ability is required to perform this installation. Many “do it yourself” backyard mechanics will find this project rewarding.  However, installation is sometimes best done by a professional mechanic.  A rewarding joy and challenge can be found in designing a custom installation of your own.  As with all motorized bikes it is essential that the front and rear wheels have good brakes to ensure safe operation.   Front wheels with disc brakes are a good option and may be obtained at most bicycle shops.   If you want a long life rear wheel axle consider using the Gru-Bee heavy duty rear axle hub kit designed for motorized bikes.   Break in your engine slowly with a rich oil / gas mix of 16 to 18 parts oil to one part gas in the first tank full.  Remember, a quality installation and engine break in with the right oil mix is paramount to safe usage and long term satisfaction.  Have fun and good luck on your motorized project.   Happy trails:

If the rear frame tube from the seat down to the pedal sprocket is too small to fit the rear engine mount, a rubber shim can be made from an old bicycle rubber inner tube. This also helps reduce engine vibration.

 
B.   The engine comes with a drive sprocket to match the chain in the kit.  It can be a standard bike chain or the 415 HD chain depending on how the kit was ordered by the WD.  If the kit has a standard bike chain and a 415 HD heavy duty chain is desired, you must remove the narrow drive sprocket from the engine and install a wider tooth drive sprocket obtained from your dealer to match the 415 chain.   Install chain with master link clip on inboard side of the primary drive sprocket teeth. ( Note: wide tires 2.25 or larger may rub on a wide 415 HD chain: )

A.  Use supplied spark-plug wrench to turn engine crankshaft sprocket to feed chain around it.  Do not pry  sprocket with a screwdriver or similar object as drive gear is made of harden material and may fracture.

B.  Fit chain, measure and remove excess links to assure proper length.  Proper length is when top side of drive chain has ¼ inch to ½” deflection with the bottom side of the chain loop tight.
Reconnect the master link, and replace cover plate on engine.

F.  Chain tension adjustments can be made by moving rear wheel.  If both engine and pedal chains can be   made to have equal tension then installing the idler assembly will not be necessary.  Mount the chain idler on the wheel strut if the engine drive chain cannot be made as tight as the pedal chain.

G.  Install supplied chain safety guard by attaching to engine and wheel axle struts.

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The spring is placed inside the cylinder slide and is compressed when the throttle is twisted.  Be sure it is seated all the way inside the cylinder. The spring then forces the throttle to return.   For this to work properly the throttle must twist freely on the handle bar in both directions prior to the cable being installed.  
Note:  All SkyHawk engine kits come with throttle cable pre-attached to the carburetor. 
           ( Above steps for cable hook up are not required with SkyHawk kits.   Ref. only)
A)  Install twist grip throttle on right side of handlebar end.   On some bike handle bars it may be necessary to ream out the handle ID to fit the bar so that the throttle will twist freely.
B)  Mount the carburetor on engine intake tube and tighten clamp screw.  Adjust engine in the bike frame so carburetor sets level as possible.  Note:  The air/fuel mixture screw should be preset at about 3.5 turns counter clockwise from the totally closed position.
*NOTE: Do not back-off screw more than 4.5 turns or vibration may loosen the screw and cause it to fall out.

Gas and Oil Mixture for Fuel ratio
The engine is a 2 cycle design, therefore, a gasoline/oil mixture is necessary.  During the break-in period (1st gallon of fuel), the ratio should be 18 to 20 parts gasoline to 1 part oil.  After the break-in period, the ratio can be increased to 20 - 25 parts gasoline to 1 part oil.

 !WARNING!  Remember safety first:  Wipe up any spilled fuel.  NEVER fuel a hot engine or smoke while re-fueling. This could result in sudden fire, personal injury.  Always move your motorized bike at least 10 feet from any fueling area before attempting to start it. Never leave the tank fuel cap off after fueling as rain water will contaminate the fuel and cause engine failure.     

# 1. How to Adjust Clutch if signs of slipping or squealing are encountered :
A)  Disengage clutch by pulling handle bar clutch lever inward and lock into catch lock.
B)  Remove right side engine clutch cover and remove small locking screw on center *Clutch Adjust Nut.
C)  Pull clutch arm on left rear engine inward.  Back off *Clutch Adjust Nut  ¼ turn counterclockwise.
D)  Release handlebar clutch lever and check for slight 1/16" free-play on engine clutch arm.
E)  Readjust *Clutch Adjust Nut as required to get required 1/6” clutch arm free play.
F)  Tighten *Clutch Adjust Nut on clutch plate clockwise until just snug.
G)  Then re-install small locking screw in outer edge of *Clutch Adjust Nut .
H)  Good idea to place a small gob of grease at gear mesh area. Use grease sparingly! Then replace cover.
I )   Squirt light grade oil down clutch cable sheathing to reduce friction and make for easy lever pull.

There are  TWO SKYHAWK GGG MODELS:    GGG-1 and GGG-2
We call these the “Give Gas Go” models = GGG

There has been a lot of confusion about these two models in the field.   Both look the same from the outside but are different.    GGG-1 has a wet centrifugal clutch, uses different crankshaft, side cover plate,  magneto, output shaft and output drive sprocket.    GGG-2 uses the standard friction clutch engine as well as a special dry centrifugal clutch and a side cover plate without oil plug.     Both models have advantages based on operator preference.    GGG-1 is less expensive and the GGG-2 is more costly.