The tach at bottom was supplied by Tom Kullen in the US.
Prior to that I waited for a year or so for stock to reappear at the Spares Co., no luck.
It worked perfectly for two weeks then went haywire.
Tom Kullen was certain that the issue was with my installation, so much testing and checking went on. It did seem likely that the problem was self-inflicted, so I temporarily mounted the instrument on my other Rapide as a check. That bike has a totally different style of ignition, D type distributor. Great care was taken with the temp installation, but the problem persisted.
Finally, I was contacted by another Vincent owner in Australia who had the same tach and the same problem. Tom said that these two problematic instruments were the only ones he had seen after a large number of sales. He was doubtful that there was anything wrong with the instruments, he still felt that something amiss with the installations was creating these problems. He also stressed that there were no new units available to exchange with, so we would be best to figure out a way to get my unit working somehow.
I still don't quite understand how that situation could occur.
Shouldn't a manufacturer always have a few spares on hand?
Or the facility to provide one after a short wait?
Anyway, Tom figured that if something had happened to the instruments, that must be due to the some unique situation with the Vincent ignition.
The problem with that theory is that while the Australian owner's bike has a stock mag, stock Vincent ignitions aren't really much different from other magneto equipped bikes of that era. Also, my 47 Rapide has a converted Norton twin point twin coil setup. The 49 has a D distributor as mentioned, so we were seeing the same problem with 3 bikes, all with different ignitions.
After exhausting the possibilities of improper installation, it did not seem likely that it was a Vincent problem, things were instead pointing at a Smith's Electronic instrument problem. The Rapide owner in Oz had also done a ton of time consuming troubleshooting . He came to the same conclusion.
Eventually we both sent our instruments back to Tom and he forwarded them to Smith's in the UK.
In due course they were repaired and sent back. Apparently both suffered burned out diodes.
A small resistor was added to the wiring on reinstall.
So full marks to Tom and Smith's for eventually doing the right thing regarding warranty and repair.
After spending days on all the troubleshooting, there was in no hurry to reinstall the thing and suck up more days, should it fail to work properly. Afterall, I purchased it in July 2014, had trouble 2 weeks later and struggled with the troubleshooting on and off for over a year before Puca agreed to take the tach back for a look. By the time it arrived in a repaired state I had owned it for a year and a half, out of which it worked properly for a total of two weeks.
So I left the repaired unit in a box for about a year until I finally got up the interest to reinstall it.
So far so good.
I think it looks just fine with the original Smith's 5" beside it. I'm not a stickler for original details anyway and this bike is the kind that gets low murmurs of disapproval when inspected by the conkers crowd.
80mm case. Puca/Smith
Glen