GT750 Speedo not working - ? options to check

[MikeH1A]

Slowly working my way through the bike. Thanks to Allan and the rest of you guys for the helpful pointers to date. I've sorted the petcock and that diaphragm problem, replaced the rubber boot between the carbs and aircleaner (old one was smaller - (? off a 550 or something), rebuilt the carbs and she's running pretty sweet at the moment

Next job; The speedo doesn't go and I'll need to get that sorted to register her. The cable is complete and turns freely but nothing happens. Any thoughts on what to be pulling apart and checking?

Thanks

[Suzsmokeyallan]

That can be fixed, see this link http://gaugerestore.webs.com/" onclick="window.open(this.href);return false;

[H2RICK]

The cable is complete and turns freely

Let's clarify this a little, Mike.

If you put the bike up on the centre stand and raise the front wheel off the ground (with the cable disconnected from the clock end) and spin the front wheel in the correct direction does the drive wire in the speedo cable turn properly ??
AA) If not, then you may have installed the speedo drive incorrectly inside the wheel hub......or you may have other problems with the speedo drive....possibly worn bits.
BB) If cable works properly then talk to Allan because your clock may need attention.

[MikeH1A]

Good idea I went out to the garage and did as suggested. With the wheel up and rotating, the cable doesn't spin at all. So, this would suggest the problem is down at the wheel end I guess. Are there particular things I should inspect or look for in the drive mechanism?

[advant63]

i have seen the tabs on #15 get flattened out so that the wheel doesn't drive the gear.

[H2RICK]

Yep, Dennis, that's exactly what I had in mind.
Mike, you'll have to pull the cable first and check the drive wire to make sure it's not twisted off inside the casing. If that's all okay, then the front wheel has to come off and the speedo drive bits all have to be inspected THOROUGHLY.
I'm betting you'll find that the drive piece with the two tangs (#15) was not engaged properly and is now flattened out and won't drive the cable properly. The tangs/drive piece can be straightened out......
CAREFULLY......and then reinstalled correctly.

[oldjapanesebikes]

Is Rick points out, this is a common problem. I posted a photo of the disassembled drive unit here. The next time, I'm just going to build the tabs up with a bit of weld and grind it back.