Wobbly central speedo....

[robinhariyadi]

Hi. I just a bought a new 200km/H Smith central speedo.

My engine is Japan domestic market distributorless spi / MPI. Automatic (of course).

But the speedo is wobbly. Jumping up and down. The cable is 26" long.

Any hint? Thanks

[richard1]

Tarija and Santa Cruz, Bolivia

Bouncing speedometer needles are either caused by sharp bends in the cable or binding, or dirt on the speedometer cup that draws the magnetic force, making occasional contact instead of spinning freely. Also, occasionally there could be dirt of corrosion in the small bearing where the pin on the cup rotates.

First check out the cable, drop some lubricant down it (the self drying with moly or graphite is great, but I often use 10W-30 motor oil). then make sure there are no kinks.

If that doesn't do it, you need to take out the head and clean it up.