Motorcycle Repair: CB77 Speedometer - Tach not working

Question
QUESTION: Good afternoon Mr. Silver,

I won't take up too much of your time, but I do appreciate your input a great deal !

I recently purchased a 1966 Honda Superhawk, in great condition, however, the Tachometer on the Speedometer is not functioning. When the bike is revved, the Tach just spins slowly in a clockwise direction.

The Speedometer currently on the bike is the version where the Tach runs Clockwise and the Speedometer runs Counter-Clockwise.

From the reading I have done so far, I am gathering that this Speedometer is from a 1961-1964 CB77. maybe you could tell me if this is correct?

Again, from what I have read, my understanding is that the other version of the Speedometer (1965-1968, I believe) where the Tach runs Clockwise and the Speedometer runs Clockwise is what should be on the 1966 CB77.

My real concern is this... Are the two Speedometers interchangeable (i.e. in today's language... Plug and Play !). I am concerned about the gearing in the units working properly!

My goal is to debug the reason for the Tach not functioning and to find a solution.

I much appreciate your help and I enjoy all of your articles and comments. They are always so helpful.

Thank you very much.

ANSWER: Kevin, the speedometers are interchangeable for the most part, however the early "reverse needle" units have a specific drive unit in the front wheel to turn the cable counterclockwise. If you want to use a later speedo you have to change the speedo drive in the front wheel.

The meters can be repaired by competent repair shops. I use "Foreign Speedo" here in San Diego for meter repairs. They were not designed to be serviced or repaired, but they can be done by experts.

The changeover from early to late speedometers came in early 1965 at CB77-1001730.

Bill Silver


---------- FOLLOW-UP ----------

QUESTION: Hi Bill,

Thanks so much for your reply.

From what you are saying, then, my '66 should have the later model Speedometer. Interesting. The previous owner of the bike must have changed the drive unit on the front wheel, as the Speedometer is functioning okay (it is my Tach that is wonky!). Is there a way to clearly identify if the drive unit is one that turns the cable clockwise or counterclockwise?

As a side note, although I call the bike a CB77, the VIN, on the motor, is actually CP77E1001785. Is there anything you can tell me about this? Is there a site where I can enter the VIN to find the true build year? The person who I bought the bike from had owned it for 40 years, so I am pretty sure it is all original.

Thanks very much for your help and expertise on this.

Regards,
Kevin.

Answer
Kevin... according to the CMSNL site microfiche your bike should have had the early speedo-tach from the factory.

http://www.cmsnl.com/honda-cp77general-export_model14957/partslist/?model_q=cp77  

"Reverse needle" speedometer drives turn the cable counterclockwise. If your speedometer works okay, then it has the matching drive unit for that meter set.

The tachometer sides are all the same, so when they go it is generally a meter issue, unless you had a really bad cable.

The omission of leaving out the CP vs. CB77 makes the question different. While based upon the CB72-77 architecture, there are detail changes that make them not follow the "rules" for most Super Hawks.  With the low serial numbers on your bike, it is certainly a 1965 production version, as they began the 7 digit serial numbers in 1965. Yours is only the 1785th bike built that year. I have noticed that through the years, many "domestic" bikes received modifications before they were included in later models for US consumption. Domestic and CP models received the alloy forks way before the US models did, for instance.

If you are getting it registered, go ahead and do it as a 1965 model.

Bill Silver