For my GT750 project bike, I was faced with the option of either rebuilding or replacing the gauge set as I was starting with just a box of bits as seen to the right. I have been collecting these for many years, and had been using them as a source of parts for my other two GT750 bikes – as a result, what I had was quite a jumble. Fred, the Calgary GT guru was kind enough to let me poke through his own bin of gauge parts and pieces so between the two I was able to rebuild something that works.
There are several ways to rebuild these – the best write-up I’ve seen is by Paul Franchina who wrote an article published in 2004 for the VJMC member magazine and which also appeared in 2005 on what is now a dead speedometer repair web site. If you are a VJMC member, then you can find the VJMC version in the 2004 member archives, otherwise you can download a copy of the 2005 public web article from here. Getting the chrome ring off and then re-installed is the hardest part, and rather than prising it off as Paul describes, a second method some folks use and which can be simpler to do is to use a small cut-off wheel (on a Dremel for example) and just cut the ring, rather than trying to prise it off as described in Paul’s article. To reinstall the cut ring, the suggested method is to use a similar clamp/jig setup as Paul uses, but then use epoxy glue to fasten the ring which is held in place and positioned using gear clamps. If done well, the cut is not easily visible, and as the ring is not deformed in any way, the ‘fit and finish’ is a bit cleaner. Of course should you ever have to take the gauge apart again, you will have a bit of a problem because of the glue, but it can work quite well. The best option of course would be to replace the ring with a new one, but a special tool would be required to reset a new ring on the gauge housing. I have been talking to Wolfgang Haerter who does this using a lathe and tool he made for this purpose when restoring Laverda gauges, but it isn’t an option for most shade tree mechanics. The ring size he uses appears to be about the same size as is used on the Suzuki gauges so I will likely have him give this a try in 2009, but of course he doesn’t have anything to fit the water temperature gauge, so I’ll have to sort that out myself.
Gauge sets are available fairly often on eBay, but generally suffer as they are obviously 30 to 36 years old, may have been sitting outside in the weather etc. and the speedometer usually is missing the trip meter reset knob as this is easily broken off or lost. Generally these will start at about $50 USD for a single gauge through to whatever level people get carried away with during the bidding. NOS and professionally rebuilt GT750 gauges are available from GTReiner in Germany, and sometimes from folks like Paul Miller in the US. These new or professionally rebuilt gauges will range in cost between about $200 USD to $400 USD depending on exactly what you are looking for – the plastic housed gauges on the early models usually cost more than the metal housed gauge sets used from late 1974 onwards.
Here is where I got to (just ‘click’ to see a larger photo). You will note that the water temperature gauge is brown. The brown faced gauges appeared on the GT750 in late 1976 through 1977 and so in keeping with my theme, would likely have been used also in 1978 had a GT750 continued to be made. I have a brown faced tachometer which I will be rebuilding at some point in 2009, and am keeping my eye’s open for a brown faced speedometer, but for the moment will make do with the most common blue-green coloured ones as I had enough parts to put one set together.