If you're a rider you know that engines won't last if you don't take care of them. Because these aren't car or motorcycle engines, however, there's no manual out there on what to check before, during, and after your rides to make your motor last. There's nothing worse than no information, but we're here with some tips to help your bike and engine last for miles to come!
Pay attention to three main areas around the engine. While the engine is cool, carefully snug up the 2 nuts securing the carburetor intake manifold, 2 nuts securing the exhaust, and tighten the 4 nuts on top of the cylinder head. Use caution to not over tighten nuts and bolts. Finger tightening to a max of 5 pounds of torque should be sufficient. Around the rest of the motorized bicycle, tighten and secure every nut, bolt or screw as often as possible.
Front Wheel & Fender:
The wheel is secure, the wheel is true, the tire pressure is correct, the tire bead is seated properly and uniformly across the rim, and the fender strut nuts and bolts are attached.
The wheel is secure, the wheel is true, the tire pressure is correct, the tire bead is seated properly and uniformly across the rim, the chain does not rub on the tire, the coaster brake arm is attached (when applicable), the wheel bearings are within adjustment and there is no play or tightness in the bearings.
How to Adjust the Rear Wheel:
Adjust the rear wheel in the dropouts if engine chain rubbing occurs. To either center the tire into position or adjust chain tension, loosen one side axle nut and then pull the portion of the wheel closest to the bottom bracket towards you and then re-tighten that side axle nut. Then, do the same to the other side until the rear wheel has the same distance between the engine drive chain and the right side chainstay… i.e. loosen the right axle nut, pull the wheel to the right, and re-tighten the right axle nut; loosen the left axle nut, pull the wheel to the left, and re-tighten the left axle nut. “Walk” the wheel back until both chains are tight and the wheel is centered between the two chains and not rubbing.
Coaster Brake Warning:
Never move the coaster brake arm once either axle nut has been tightened. Bearing adjustment can go out of whack if you don’t pay special attention to how and when you position the coaster brake arm. To remove a coaster brake wheel, detach the coaster brake arm bolt first then either side axle nut. To reinstall a coaster brake wheel, slide the wheel into position with both chains on their sprockets, tighten the coaster brake arm hanger, loosely tighten the right side axle nut, and then the left side axle nut. Next, follow the procedure above for “walking” the wheel into position.
The chain tensioner acts in many ways the same as a derailleur guiding the chain onto the sprocket. With the clutch in, check that the tensioner guides and centers the chain onto the sprocket teeth in the middle of the chain. If you have to reposition the chain tensioner to adjust for chain slack or if the tensioner gets knocked out of position somehow, make sure that the chain tensioner is fastened with self-tapping screws to support the sideload that occurs during engine start-up and overrun/deceleration. Always keep a half-inch to an inch of slack in the engine drive chain.
Clutch Free Play:
Too much clutch free play or too little clutch free play will not allow the engine to engage. Adjust the free play as needed, either on the clutch lever at the barrel end adjuster for fine adjustments or on the engine at the clutch arm’s cable stop for gross adjustment.