After getting my CB77 up and running again after winter and for MOT I've found that the speedo and rev counter are acting crazy going in bizarre directions and hitting full scale at low speed. Now the speedo works but the rev counter doesn't.
Is this normal behaviour, is it fixable and are their any experts who can fix these things in the UK?
Many thanks
CB77 speedo clusterRe: CB77 speedo clusterOften it's just a case of 'stick-slip' caused by a dry cable or input bearing. The cable stops for a moment, winds up then releases the energy causing the needle to swing violently.
Try running a couple of drops of oil into the input bearing of the tachometer and lubing the cable. If that doesn't work the unit may need stripping and lubricating. I've stripped a few down and restored them but I'm pretty tied up for the foreseeable future. G
Last edited by G-Man on Sat Jul 22, 2017 3:35 pm, edited 1 time in total.
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F It depends how patient and skillful you are. Hardest job is to carefully prise the bezel off. After that it is simply a job of dismantling small mechanical components, cleaning and lubricating them.
Here is a CL speedo bezel......  You just work around easing up the edge of the bezel until you can remove it. With th ebezel and glass off you have to remove the needle(s). This is done by putting some cardboard packing over the face and easing up on both sides of the needle with something like a teaspoon handle. The needle will fly off so cover with a piece of light cloth. The inside will look a bit like this.....  Clean with solvent and lubricate with grease and clock oil sparingly. There are some walk-throughs here if you do a search. G
Last edited by G-Man on Sat Jul 22, 2017 3:35 pm, edited 1 time in total.
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F Hi,
I had just this problem with my restored CL77, wild swings to the needles, screeching noises from the speedo and a needle that took forever to return to zero when stopped. Like you I didn't fancy much stripping it down, or really trying to get it back together. I took off the speedo and placed it faced down on the bench and then added two or thee drops only of thin oil to the cable connection and left it like that overnight. We get something over here called Three in One Oil and I used that. I'd heard that some after market speedo cables had an inner cable slightly longer than it should be but again I didn't want to start chopping the end off the cable. Solution was to put a small 'O' ring inside the speedo cable end coupling which effectively lengthened the outer cable instead. Result was a fifty plus year old speedo which is rock steady and accurate too. I did that four or five years ago and the speedo is still behaving perfectly, I might just have been lucky but it could work for you too, certainly worth a try.
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