|Tech Tips by Randy Pozzi|
|Tech Tip #35 Honda CH250 Engine Hanger Bushing Replacement|
Over the course of scooter ownership, especially with two-up riding, your engine hanger bushings may become sloppy and need repair. Tell-tail signs are excessive engine vibration and side-to-side play of the rear wheel.
The Honda CH 250 is not a full frame scooter. It is a sub frame scooter with what the industry calls a fish bone frame. The engine, transmission and rear wheel are a unit suspended from an engine hanger with bushings and o-rings to guide up and down movement. Over time the o-rings become worn and the inner bushing wears unevenly. There also is no dust seal to protect the bushings from moisture and dirt and no grease zerk to lubricate.
This unit pivots along with shock dampening to provide the rear suspension. This engine hanger is attached to a rubber-isolated engine sub-assembly bracket to reduce unwanted engine vibration. On each side of the engine hanger is a bushing, two o-rings and an inner engine hanger bushing Because the outside bushing has been discontinued, you will have to re-use your existing bushing and replacement of the inner bushing and o-rings is all that can be done.
Parts note: If you have the 1985 CH 250, the outer bushing, 11104-KM1-670 ($8.63), has been discontinued. The inner bushing, 11105-KM1-670 ($8.56), and o-rings, 91354-671-004 ($1.71) is available. If you are just replacing the inner bushing and o-rings, those part numbers are good. However, if you are replacing all the bushings, use the Honda Helix bushing package. An examination of the crossover parts used between the similar Honda CN 250 Helix reveals that the Helix bushings as a package will work. Those parts are outer bushing 11103-KJ9-750 ($8.29), inner bushing 11105-KJ9-750 ($10.14) and two o-rings 91304-KJ9-MJ0-003 $1.86).
The good news is you do not have to remove the engine from the scooter to replace the bushings. You will, however, need to remove some parts to get to the bushings. Place your scooter on the center stand. Remove seat, center cover, left and right side covers, and the bottom bolts on each rear shock. The engine can be lowered down and one inch to the rear after removing the engine hanger bolt.
Although the two inner bushings, which sit inside the outer bushings, may easily be removed with your fingers, the outer bushings are pressed into the crankcase, and need to be pounded out with a bushing removal tool. They must be pounded out from the inside of the case.
Tip: If you remove the inner bushings from their respective sides, turn them around and insert them into the backside of the opposite outer bushing, they can be used as a driver to remove the larger outer bushing. You will need a long-handle bushing driver because you will need to remove the farthest outer bushing from inside the bushing cavity from the opposite side of the crankcase.
You can make a tool that works. The tool that can be used is a 16-inch long piece of ¾-inch round stock steel that has a turned down 1-inch long end tip that is reduced to .370 inches. That end fits inside the inner bushing cavity. Use the tool to install the new bushings into the crankcase bushing cavity. Then re-install the engine into the scooter.
The “Scooter Guys” Tom and Joel contributed to this Tech Tip.
Randy Pozzi (01/09)
and maintained by doug Elam