Forum

[ChrisD]

Gentlemen – I seek advice. I have the same speedometer waving issue on my 1996 535cc Bullet that many others have. I have sought the answer with new speedo, new drive and new cable to no avail.
On testing, both speedo’s are rock steady if connected to a drill.
But on the road, the needle wags some 30-40kph width all the time. BUT if I pull in the clutch and release the throttle, freewheeling down a hill, then the wag stops almost instantly – even on a bumpy road. In fact, during freewheeling, the speedo consistently overreads some 10% at whatever speed I am doing (tested between ~30-110kph) when compared to the GPS-set bicycle speedo on the handlebars so I am happy the speedo and drive work correctly. This tells me that it is not a mechanical fault causing the wag but some sort of induced magnetism in the casquette from the manual throttle position. So what is causing it and how can I insulate the speedo from the throttle? Has anyone else encountered this? I am sure I've seen a comment like this on a bulletin board, but which one and when. NB: everything else in the casquette is standard OEM stuff from the late 90’s. Maybe if I stuck a couple of magnets on the casquette I'd get some other response.
Cheers, ChrisD

[Spudgun]

This problem turns up, every now and then.

The speedo on my Lightning is rock steady at all speeds. Why? There are no kinks along the run of the speedo cable. Mind you. I don't have the casquette.

When I had a D10 Bantam. The needle would wave about (Pressed steel 'casquette'). It took a fair bit of effort (and bending of metal) to eliminate any tight turns for the speedo cable. Once done. The needle was steady.

It's the cable run that's the problem.

[Wheaters]

Yes, the wavering speedo needle is most probably due to the flexible inner cable binding very slightly in the outer, then releasing. The tighter a bend is or the more bends there are in the run, the more likely it is. It doesn’t tend to happen if the cable run is straight for obvious reasons.

Pulling in your clutch cable might be helping by pulling the speedo cable slightly straighter at the place where it’s binding.

Despite what many advise, I’ve always lubricated the inner cable (taking care not to get lubricant in the speedo head) because if there’s any rust on it, the more friction there will be.

[stinkwheel]

Could it be that your forks compress slightly when you come off the throttle and extend slightly when you open the throttle. Enfield forks being what they are, they then tend to stay in that position until something else happens. So perhaps cable routing?

[ChrisD]

Gents. I shall revisit this once the bike is up-and-running again. I had revved the bike to over 7500rpm (in a fit of something). The UK mains and roller big end and steel conrod handled it quite well except the inlet pushrod slipped off the tappet due, I suspect, to valve bounce at those revs. Anyway, I found the oil seal jammed on the inlet valve guide and, once the engine was cold, I pulled at the plastic seal and the valve guide moved out a bit!! So I took the head off and put it into hot water (~50degC) with Prepsol to clean it and tapped the guide out using my fingers only. Measuring it I discovered it was 2thou smaller than the standard size (which is 0.625”) and with a non-RE code stamped on it. Wonder where it came from? Sooo I’m about to order more parts. Cheers, ChrisD