speedo and tach drive ratios?

[cafeniky]

Looking for the speedometer and tachometer drive ratios so I can replace them with mini's on my cafe project.

The bike is a '79 GS750L

I have been searching for the last 2 hours and have come up with nothing, any help would be greatly appreciated.

[MrSelfdestruct]

tach = 4:1
speedo = 2240:60

I'm doing the same, and it took me a while to find too

[GS1000G Shopper]

A little late to the game here, but are these ratios universal? I ask due to swapping a 140 MPH speedometer onto my '81 1000G (was 85 MPH) and it reading 5 MPH fast (compared to GPS) at 70 MPH. If you can site a place to find what you found, it would be appreciated.

The parts lists I've looked at indicate nearly every GS shafty used a 54600-18401 drive assembly. One list for my bike showed 54600-18402 replacing 18401. During this time frame, the speedometers went from normal down to 85 then back to normal.

[MrSelfdestruct]

more or less every japanese bike from the 70's/80's used the 2240:60 ratio. 5 mph error @70 sounds about right...I bet your car speedo is about the same. I got my mini speedometer (with idiot lights and led backlight) from mike's xs (xs650 site) because it's a pretty universal speedometer ratio. xs650s use a 5:1 tach ratio though, so I had to get a matching tach with a 4:1 from JC whitney. After having them on the bike for a few months I can say that mine reads a little optimistic as well, but it is a lot closer than the original speedometer. The tach is right on the money though. I'll put some pics up if you're interested.