4
Figure 1.
Bike with wide frame or big down tube: Use ¼” thick 1-1/8” x 2-1/2” steel plate with one hole in the
center for a bolt to go through a drilled hole in tube frame and two holes for cap screws to go into
engine block. Additional spacers may be required depending on the donor bike. Make sure the 2
M6x18 screws do not bottom out in the engine block threads or a cracked crankcase might happen.
Figure # 1
3.
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.
Engine needs to have the carburetor set in a level position.
Too much engine tilt can cause chain to hit
the drive cover and the engine to not run correctly due to float angle.
It is best to have the drive
chain to rear wheel sprocket be as horizontal as possible with no more than 15 degrees max engine
tilt.
After the desired engine location is determined mount the engine to frame. Appling LocTite thread
lock is recommended to avoid loosening due to vibration.
Note:
All threads are metric
.
Chain Wheel Sprocket Installation:
The Drive Chain Sprocket has a 36.9 mm dia. center hole and mounts on axel hub on the left side of the
rear wheel against the spokes dish side in. The sprocket must fit over the hub in a perpendicular plane with
the axle. This insures that your rear chain sprocket spins true with the rear bike wheel.
*NOTE:
On some
older bike axle hubs like on coaster brake models it may be required to slightly enlarge the sprocket center
hole to obtain a flush, and concentric fit next to the spokes. This is best done on a engine lathe by a
professional machinist.. . It is also recommended that the rear wheel be re-spoked to 12 ga. spoke wires to
insure long life. Most any Bike shop can do this operation for you. Applying thread adhesive and equal
tightening of the sprocket bolts. This keeps the chain sprocket true with axle and free from wobble while
spinning. With bike upside down spin wheel and check sprocket for wobble. The chain can jump off the
sprocket if the sprocket installation is done incorrectly
1.
For kit sprocket installation, locate sprocket on axel hub with curved side next to spokes, shinny side in.
If not pre sliced, cut the rubber isolator ring between holes in order to fit INSIDE the spokes and around the
axle. Install the split steel retainer plates next to the rubber isolator and insert 9 bolts.
2.
Secure with 9 bolts compressing the chain sprocket to the spokes. Note: Rubber isolators may be needed
on both sides of sprocket for chain alignment.
