Smiths Tachometer Repair

[Big Phil]

Hi, The Tachometer on my Spitfire MIV has suddenly failed. The needle started flickering wildly from 0 to 10k and then stopped completely before recovering for a few miles then stopping completely again. I can actually hear a distinct whining noise when the engine is ticking over coming from within the tachometer itself.

Can anyone kindly recommend someone who can repair and refurbish the instrument which is a Smiths RSM 3003-06 grey faced type.

[tdc]

If you do an internet search you will find lots .Good luck !

[hoogerbooger]

Magnetic?

Have you double checked it's not the cable?

Has the cable been greased recently? Dragging cable causes needle flicker. No change to the cable run? if the head has been off & now back over tight on a cable that is a tad too long it can cause drag and flicker. If one end of the cable twists off it'll stop working.... I've had all these.( but on a magnetic speedo)

As for the head if you have an old cable end...or using the whole cable inner..... check if it turns freely. If you have an old end of 6-8" run it off a drill ( not too fast. Start slow)(but hold the middle of cable to stop it flicking around). See if the dial will run without flicker.....if so it's not the head.

When the head on mine was not smooth to turn( sounded a bit dry/ slight rubbing)  I used a few drops of bicycle Teflon dry lube dripped in carefully to seep between inner and outer at the cable entry point. Spin it a bit with the cable. Then stand it face up to dry as you dont want it getting further in ( it'll collect dust). Worked for me. Stopped the flicker( and removed the slightly metallic rubbing noise it was making)

[MJM_58SR]

Try Russell at chronometric repairs in Nottingham.

[V500]

Or Ashley Pople.
If the instrument head is making a strange noise I don't see how the problem could be cable-related though.

[hoogerbooger]

Or Ashley Pople.
If the instrument head is making a strange noise I don't see how the problem could be cable-related though.

( Agree, probably not. More likely head itself.  Not sure  though if the cable/ washer location is too long whether it can press hard enough to cause rubbing within head. I think my cable is a bit too long. When I last reinstalled I seem to have done the nut up too tight and got mad flicker going off top end of dial. Loosened it a bit and it was flicker free.)

[V500]

There's a difference in the driving "nose" length (the portion protruding beyond the nylon washer) between Chrono and magnetic speedo cables though. if loosening the nut cures your problem it would point to this being at least part of your issue.

[Big Phil]

Thanks for all the replies and suggestions much appreciated. I sent the tachometer off today for a repair and refurb. I'll let you know how I get on and who's doing the work once I get the counter back. It's a 3 week turnaround.

[Big Phil]

Hi, I just wanted to provide an update on my Tachometer repair. I sent it to Classic Speedometers in Mansfield run by Stuart Walker for a fixed price "Service and Repair" at a cost of £110 +£10 postage with an estimated lead time of 3 weeks. My tachometer was returned just a few days over the 3 week estimate, extremely well packaged. I could see immediately the bezel and glass of the tachometer had been replaced with new parts. Furthermore the needle and face of the tachometer had been refurbished and cleaned making it look like new. I fitted it to the my Spitfire and it worked perfectly. I've now covered about 100 miles on the bike and the tachometer remains absolutely stable both at tick over and out on the open road. Can't recommend Stuart highly enough. I have no connection with Stuart whatsoever other than being a satisfied customer.

Regards
Phil

[Allan G]

I had this on an old tacho some years ago, the screech was horrendous. I removed the clock and sprayed some ACF50 through the bulb orifice. (My thought at the time was if it doesn't cure it, its buggered anyway)... Anyway it worked a treat and it ran on the bike for a few years with no issues. I eventually had it and the speedo rebuilt and its been great for about 10+ years.

The rule of thumb is you DON'T spray anything into magnetic speedos/tachos... but if your prepared to have it rebuilt, then what is the loss?