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Discussion Starter #1
How do you determine if a gauge can be swapped to a bike it wasent intended for?

I need smaller and nicer looking speedo/odo/tach for for my 79' CB650.

also, if i were to find a combination gauge that had a fuel gauge on it what would you need to do to make it work?

any links to cool gauges or pictures of cool gauges would be appreciated as well.
 

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you look up the donor bikes speedo ratio and see if it matches yours. Same for the tach. You'll probably be in luck with the speedo as there are only a few standard ratios (I think all jap bikes are pretty much the same - 2240:60 - but I could be wrong). Speedos are never dean on accurate anyway. Tachs are a whole different ball game, the ratio depends on the engine and can be anything. cb750s and cb550s share a lot of small parts but they have different tach ratios and the gauges won't swap over. Your best bet is going with an electronic tach. You can find out if a tach is acurate by hooking it up and then getting a dwell meter that also measures rpm and checking it against that.

As for the fuel gauge that is going to take some fab because you are going to have to get the existing fuel sender to work in your old tank, this could be as easy as adding a bung to your tank or as hard as sectioning part of the old tank into the new one. Personally fuel gauges on motorcycles are for sissys, you wanna know how much fuel you have open the lid and look or clock it on your trip odometer.

So what gauge do you have in mind? Personally I have expirence retrofitting cb450 black bomber and cb77 superhawk headlights/speedos to cb750s, and I have done a yr1 headlight/speedo on an rd350.
 

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did you see that article in cycle world about the tachs on new bikes and how out they are??? pretty interesting. speedos can probably be affected alot by tire choice.

jc
 

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quote:
I need smaller and nicer looking speedo/odo/tach for for my 79' CB650.
any links to cool gauges or pictures of cool gauges would be appreciated as well.
J.C.Whitney had small tachs/speedos a while ago.

FC
 

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You should be able to match up the fuel gauge without changing sending units by trying a inline resistor. For instance...if your new guage reads high all the time, try installing a resistor in the wire to the gauge...to bring it down.

However if it reads too low...you might be out of luck...unless you can find a tuning resistor in the system somewhere to remove. A clever person might even be able to add a small potentiometer in the system to tune the output signal of the sending unit.
JohnnyB
 

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Discussion Starter #6
right now im just kinda looking around for gauges, nothing in mind yet as i havent known what would work. In my mind i would like a black face with silver or white numbers and a metal needle. I dont really care about having a gas gauge but if i found a tach or speedo i liked with it already built in i want it to work.

Do they make electronic tachs with an analog face? If not ill probably just chuck it altogether...bad idea?
 

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quote:
right now im just kinda looking around for gauges, nothing in mind yet as i havent known what would work. In my mind i would like a black face with silver or white numbers and a metal needle. I dont really care about having a gas gauge but if i found a tach or speedo i liked with it already built in i want it to work.

Do they make electronic tachs with an analog face? If not ill probably just chuck it altogether...bad idea?
I've used autometer tach on drag bikes in the past, and my buddy has one on his kz drag bike, its an electronic tach with an analog face. They seem to be the standard in drag racing next to the stock tach.

cb650s don't have gas gauges so a sending unit and provisions for one would need to be added.

If you want my recomendation I would go with a cb77 or cb450 K0 headlight/speedo combo. The gauges are mounted in the back of the headlight shell. I have retrofitted a few of these to cb750s and here is my advice: You can either use the stock gauge and retrofit a jc whitney tach inside the gauge, or you can gut it and mount to jc whitney minigauges inside the housing. One way has a factory apperance but is a lot of work. The other way is simple and looks custom. The jc whitney gauges are not the best quality, cobra makes a similar minigauge for metric crusiers but it costs more and you have to know your ratio. As far as I know they do not make a companion tach. If you are going to go the autometer route, you an just a hole in the back of oyur stock shell and mount a mini speedo in there.
 

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quote:
thanks for all that info, i really like this one

http://www.jcwhitney.com/autoparts/...tom-0/p-2008923/N-111+600014720+10211/c-10111

but it doesnt give any ratio, does that mean its adjustable or when you order it you select one?
most jap 4cyl bikes use the same speedo ratio, only the v-twins might have a different ratio because they try to make them as compatable as they can with harley parts.

cobra had this tach (I found this pic under volousia parts) which I think is better quality than the jc whitney stuff but it is expensive:



they used to offer a matching speedo but I couldn't find it.

Edited by - Geeto67 on Jun 30 2006 09:02:45 AM
 
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