Topic: CB 750 Speedo issues...

[The Dude Abides]

I recently purchased a '78 CB750F, it was missing the speedometer, so i purchased an OEM replacement, but i can't get it to work. I used a drill to check the speedo itself and the cable, and both are working properly. So after searching the forums and consulting my manual, i think the issue may be the speedo gear drive? Whenever i spin the front wheel, the little prong that the speedo cable hooks into doesn't spin........so i'm guessing i'll need a new one....do you all have an opinion? I'm still trying to learn everything i can about this thing and would greatly appreciate any input you all have!

[alancop]

I would assume it was the front wheel sender. If it's not turning the cable, its probably broken.

[The Dude Abides]

I apologize for my lack of knowledge, but i believe that to be the part that the speedo cable connects to at the front wheel, correct?

This part... http://www.ebay.com/itm/77-HONDA-CB750-CB-750-F-CB750F-SUPERSPORT-SPEEDO-DRIVE-13-/350554274177?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item519ea9b981#ht_524wt_1397

[trueblue]

That is your speedo drive, there is also a little washer in the front wheel that drives that unit, it could be causing the problem, you need to do some exploratory surgery to figure out which part is causing the issue.

[The Dude Abides]

ok, i'll try a tear down this weekend and see if i can figure it out. Thanks for all of the help guys.

[Nikkisixx]

Before you do that, put the cable on the sender and roll the bike and see if the cable turns (this is easier than trying to watch the driver turn).  The wire inside the cable may not have engaged the driver completely.  How is the bike running otherwise?  I just sold a beat up old Super Sport to some sucker in Hickory....

 

[The Dude Abides]

Before you do that, put the cable on the sender and roll the bike and see if the cable turns (this is easier than trying to watch the driver turn).  The wire inside the cable may not have engaged the driver completely.  How is the bike running otherwise?  I just sold a beat up old Super Sport to some sucker in Hickory....

 

I'm sure i'm probably that sucker. I'm the proud owner of a 1978 beat up old super sport.

I put the cable on the sender and rolled the bike, and it doesn't turn at all. The wire is engaged, i double and triple checked to make sure.....

[Nikkisixx]

Sorry man.  Now we know why the speedo was MIA?
I think because of the twin disk brakes that driver is different for the 77-78 SS.  Hopefully it just isn't locked in just right and a bit of fiddling with fix it. 

[The Dude Abides]

a bit of an update on this...got the wheel off and torn down this weekend....after opening up the speedo gear, the retainer ring inside it has been stripped, for lack of a better term. two of the metal notches on it have been ripped off. So i ordered another retainer from Bike Bandit...will update after it's all back together.