Speedometer needle is bouncing

When I bought my XJ700N I noticed the speedometer needle bounced a little and I'm just now getting around to fixing it.

The odometer and trip counter does not work, the plastic backing on the odometer is cracked and the gears inside seem pretty beat up. I was wondering how can I stop my speedometer needle from bouncing or if the broken odometer is causing the problem.

I only have a basic idea of how the cluster functions on a mechanical level so please put it in novice mechanic speak.

 

BigFitz just posted a partial tear down of his 550 cluster which may help.

My needle bounced at about 50mph - lubing the cable seems to have cleared that up. But you odometer issue cold be th cause too.

 

I have a similar problem. My speedometer is just wrong, the odometer and the trip meter are dead on but the needle always runs about 10 - 20 MPH slower than I am actually going - I have test this with running with other bikes and with a GPS.

Any ideas on that one?

 

This is a common problem with these xj's. Invariably, when the bikes are tipped over, they land on the corner of the unstrument cluster. Most of the time, the distressed owner picks the bike up, looks at the damage in disgust, and proceeds to put it out of his mind the best he can. The problem is that if it was tipped over on the left side (speedo side) it loads the gears in such a way as to put excess pressure on them. It will work like that for a while, but then the gears wear out prematurely. The speedo worm gear mates with a little rack gear that turns the trip meter which turns the odometer. The gear that usually wears out the fastest is the worm gear on the speedo shaft and the little trip meter rack gear. The whole assembly is stamped and pressed together and is not easily repaired by the owner. The solution is to keep your eye open for one on ebay. If the only problem you are having is the needle bouncing, get some graphite and lube the cable up real good. If you can, also give a shot where the cable mounts to the speedo. It may do more good than you might imagine. Don't despair, even if your speedo is inaccurate, if you ride with someone whose speedo is accurate then check your speed against your tach reading and you can ride safely within the speed limits by memorizing rpm's in the various gears. Being from the US we are mainly concerned with several speeds in particular; 25mph, 35 mph, 55 mph, and 65 mph. Once you get those memorized you can guess pretty close if you need to ride in between those speeds. Best regards.

 

A friend of mine had a similar problem, just the other way, the needle was always 15 over the actual speed. He took the speedo cable completely off the bike, rode it around for 20 minutes (on back roads where the police were not very likely to be and always going very slow). Then made sure both ends of the speedo cable were straight, cleaned them off really well with Brakleen (Wal-mart) and a wire brush (Wal-mart), re-lubed them with spray graphite (Autozone), and shot a tone of Brakleen into the speedo coupling at the wheel base.

This fixed his problem. He guessed something to do with gunk in the gears causing an inaccurate reading.

 

When I did the cluster teardown (as part of a series on retrofitting a real speedometer) I also took some pictures of speedo and tach guts and what can and can't be done to fix them; how they work; etc. I'm still working on that bit, I'll have it done soon.