Tech Tips by Randy Pozzi

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#1 Breather Separator
#2 Drive Belt & Pulley Weight Rollers
#3 Startability & Driveability Problems
#4 CH250 Performance Upgrades
#5 CH250 Valve Adjustment
#6 Decals
#7 Pilot Screw Adjustment & Fix
#8 CH250 Driven Pulley/Clutch Repair
#9 Final Drive Oil Change
#10 Storing Your CH250 in Winter
#11 Hondaline Kenwood AM/FM Stereo
#12 Front Bumper Protector & Lower Cover Repair
#13 How To Buy A Good 1985-88 CH250
#14 Tires For The Honda CH 250
#15 CH250 Keihin Carb Float Valve Repair
#16 The Honda CH250: An Overview
#17 Honda CH250 Color Crossovers
#18 Honda CH250 Clock
#19 Keihin CV Carburetor Tuning
#20 Honda CH250 Oil Change
#21 Backfiring On Deceleration
#22 Parts Bin--What To Hoard For Your CH250
#23 Honda CH250 Maintenance
#24 So Your Honda Scooter Won't Start?
#25 How To Buy A Battery For Your CH250
#26 Honda CB350 Shocks To The Honda CH250
#27 1985-88 Honda CH250 Speedo Maintenance
#28 Honda CH-250 Antifreeze/Coolant Service
#29 CH250 Charging System Checks
#30  Final Reduction and Wheel Bearing Maintenance

#27 1985-88 Honda CH250 Speedometer Maintenance
Hello Group,

The speedometer is a useful tool for the rider to know how fast he/she is going. It is housed in the plastic speedometer cluster with the temperature and fuel gauges in the handle pipe of the scooter. Occasionally, some speedometer malfunction will occur which renders the speedometer erratic or nonfunctional. There are three main fixes for speedometer problems--at the front wheel, in the cable housing and in the speedometer cluster. Here is a run-down of speedometer problems and their fix:

Squealing Noise Inside The Cluster:  Also known as a dry speedometer drive. Age and hot dry weather can contribute to this problem. The speedometer cable runs from the front wheel, up along side the steering stem head into the speedometer cluster from below. The cable turns a greased bearing--the drive bearing, which then turns the speedometer pointer for miles-per-hour and numbers for miles. When the speedometer drive bearing has excessive wear or the grease dries out--squealing noise. 

To service this problem, it is necessary to remove the instrument cluster from the bike. Remove the three screws and lower instruments cover. Remove the four screws and trip meter knob, then the instruments lens. Remove the screws and disassemble the instruments.

For the digital dash used in 1985-1986, the speedometer drive is separate from the face plate. For the 1987-1988 years, the speedometer drive is attached to the face plate. After removing the cluster face plate, lightly oil the rear of the speedometer drive and the drive mechanism and reassemble. If the speedometer drive bearing is too worn, or the squealing shortly returns, the speedometer drive must be replaced.

Broken Speedometer Cable: Usually, you find this out when the speedometer pointer quits abruptly. First look to see that the end of the speedometer cable has not come loose from itís housing in the front brake panel. If not, remove the set screw and then pull out the speedometer cable from the front brake panel. Look inside the brake panel and spin the front wheel. The speedometer drive should be spinning.

If it spins, next check the function of the speedometer cable wire. With needle nose pliers, pull out the ferruled wire drive from the cable housing and insert it into a low-speed variable speed hand drill. Running the drill should spin the cable to get a reading on the dash gauge. If no reading, the cable may be broke. 

Disconnect the speedometer cable from the bottom of the dash cluster and spin the cable with the hand drill again. If the wire turns at the top, you have an internal dash cluster problem. If it doesn't, the cable is broke in the cable housing. Usually, the broken piece will be near the bottom because that's where the torque is strongest. Remove the rest of the broken drive cable from the top of the cable which was disconnected from the dash cluster. Push the broken end out with the wire end of the piece you just removed. Fasten the speedometer cable to the bottom of the dash cluster and insert the replacement wire drive  from below. Note: If the speedometer cable housing has not been damaged, just change the wire drive cable inside. That part is 44831-KM1-671, about $4. The part number for the cable housing and drive is 44830-KM1-880, about $12.

Erratic MPH Pointer: Your riding along at 35-miles-per-hour, but your speedometer pointer is quivering at 15. You increase speed to 45 miles-per-hour, the mph pointer is still quivering, and then suddenly the pointer catches up to your actual speed. You check your drive cable and itís not broken. What gives? Try bent dogs on the speedometer drive gear. Huh? After removing the speedometer drive cable from the brake hub, spin the front wheel and look into the cable housing. The worm gear should be turning the drive pin. If it intermittently rotates while the wheel spins--itís gone to the dogs. The speedometer drive gear has two ears--or dogs--which fit into notches inside the front wheel hub. The wheel turns the speedometer drive gear which turns the worm gear in the brake hub which turns the speedometer drive cable. These dogs can get bent over time from torque or when someone does not pay attention when assembling the front wheel after a brake job or tire change. To correct this problem, remove the front wheel and the speedometer drive gear. Bend the drive gear dogs flush with the end of the gear housing, then reassemble. Apply new grease to the worm gear.

Follow these tips and you'll always "be up to speed".

Question: Are the speedometer clusters between 1985-1988 interchangeable?

Answer: The speedometer clusters for 1985-1988 are physically interchangeable. However, they have wiring differences which make them not functionally interchangeable. For example, the clusters for 1985-1986 are digital readouts. The gauges for 1986-87 are analog. Even tho the digital gauges look similar, they are not. Honda changed the fuel tank sensor and the fuel gauge in 1986. The only difference between 1987-1988 gauges is that the 1988 cluster added a side stand indicator light. If replacing a cluster, obtain one from your specific year for best results.

Randy Pozzi (Rev. 07/2008)


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