|Tech Tips by Randy Pozzi
|#2 Drive Belt & Pulley Weight Rollers
Its time to change the drive belt on your CH 150/250.
Yes, boys and girls, it's a little time consuming and somewhat aggravating to remove the body center cover, left side panel and rail, pillion step and brake cables.
And while you're at it, change that final reduction oil too!
After you have removed the left crankcase cover, use a special Honda tool or one you fabricated to remove the drive pulley nut and washer and the drive pulley face.
The drive belt--PN 23100-KM1-671 or 23100-KM1-6700 (about $70)-- rests on the boss collar of the movable drive face.
The drive belt wears on its side. Honda recommends replacing it at 12K miles.
Realistically, you shouldn't have to replace it until about 20-25K miles or when you notice top end speed reduced 5 mph.
Inspect the drive belt for wear and underside cracking.
The service limit for the belt measured at the width is .83 in.
Install the new drive belt by squeezing the clutch driven pulley to allow the belt to rest.
Put the front of the belt on the boss collar of the movable drive face and then re-install the drive pulley assembly and crankcase cover.
All done right?
You missed something real important that most mechanics skip.
Inspecting and greasing the drive pulley weight rollers!
I said the weight rollers.
Although not time consuming, its often neglected.
They call it a MOVABLE drive face for a reason.
Inside the moveable drive face assembly are six hollow greased weight rollers.
As you accelerate, the weight rollers centrifugally move to the outside of the ramp plate moving the drive face toward the belt.
This allows the drive face to move inward on idle and outward on throttle and squeeze the belt upward to assist the rear clutch driven pulley.
On the front of the variator is a cooling fin cap.
Honda uses a special wrench--PN 07923-KM10000--to hold the fins while you remove the nut with an impact wrench.
Not have that special wrench?
Chuck a wedged piece of wood between the variator and top case will do just fine.
Once the cooling fin piece is off, the movable drive face assembly comes off.
Mechanics have to disassemble the drive face by removing the three 8 mm bolts, O-ring and cover.
Remove the ramp plate and inspect and grease the weight rollers.
The weight rollers--PN 22123-KM1-316 (about $17)--should be inspected for wear.
Service limit width is .93 in.
Any flat spots indicate the need to replace them.
The service manual recommends 25-30 grams of lithium grease in the variator.
If you make the mistake of overloading the weight roller chamber with too much grease, it will sling out on to the belt and cause more belt and acceleration problems.
Grease liberally but cautiously.
You also may mix and match different gram weight rollers to obtain varied performance.
Lighter weight rollers will give you quicker take-off but lower high-speed riding.
A heavier set of rollers will increase your top speed, at the expense of low speed acceleration.
The standard weight rollers are 22.6 grams, 24x18 mm. These are the same as the CN250 Helix.
Some mechanics make the mistake of first inserting the boss collar where the belt rides into the driven pulley before installing it on the axle which results in the boss collar pushing the ramp plate too far back.
This allows the weight rollers to slide side-ways out of their place.
The result--the ramp plate fails to work or works poorly and the rollers skid and wear flat.
The result--poor performance.
The rear clutch plate assembly ends up doing all the work grabbing the belt.
Regardless of what the service manual says, replace your weight rollers every 5K miles for smooth performance.
Keep these little things in mind when servicing your drive belt system.
By doing so, your belt gets even wear, your weight rollers do their job and your scoot has smoother acceleration and quieter performance.
and maintained by doug Elam