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My Tachometer quite suddenly in the middle of my last long ride. I ordered a new one, but it came into a M/C shop 35 miles away. My son is bringing me the cable Friday afternoon. We are both leaving for the Rally in Llano soon after he arrives.

I have never changed that particular cable before so here is the question. On a 1975 R90/6 – if I have the old cable removed and everything ready to go, how long will it take me to install the new one and are there things that I can get tripped on?

Or should I just go one more trip with no tachometer?

The needle was a little bouncy for as long as I can remember. It is a broken cable isn't it? I just assumed that.

If you took out the cable, the labor it took YOU should be your guide as to how long it will take YOU to put one back in. Remember as a rule, 9 times out of 10, expect more time to go into putting something back together than ripping it apart; often there a BIG difference between the two, this cable, not so much so.

99% of the tips I can think of to make the install go faster, it's sort of too late for as they would relate to how you took the old one out and left things in preparation for the new installation. Truly it's straight forward; though beware of screwing things up in the bucket while in there. I've done several and swapped several new cables and an NOS tach/speedo unit trying to see if it changed the way the "system" behaved; the only thing that comes to mind on my slightly older bikes is that the first time I got in there, I found wiring and such that needed re-worked, or was not as I wanted to see it, so much more time was spent fiddling with things not related to the cable than ever sticking that cable in there and putting the bracket and such back on.

I do not recall (or know on your bike) if you need remove the hold-down plate or not for the tach cable nut; I found I needed to. Only advise on that is, don't loose the little nuts and washers and take a very small amount of heavy grease and use that to help you maneuver the fasteners back on; otherwise you may lose count how many times you drop those little fasteners in the bucket trying to get them back on... - Unless your hands are the size of an infant's

dwire wrote: as a rule, 9 times out of 10, expect more time to go into putting something back together than ripping it apart;

[and,]

found wiring and such that needed re-worked, or was not as I wanted to see it [so I needed to spend more time and more money than I had budgeted]

These should be rules that are written down somewhere. They are profound. Also they are enough to get me to take one more trip with a busted tac.

Thanks

Glad you liked that.

I'm not often accused of saying things too profound; unless they be profoundly incorrect, so I'm indeed flattered...

At least the first thing quoted applies pretty well to just about anything I can think one might work on. There are a few exceptions. Draining a big tank and making repairs, like on an anodizer or other large plater may be much faster than it takes to refill and restart the unit. - You know, like the English language, "there's ALWAYS exceptions..."

Hmmm ... not sure what the drame here is all about.

The tach cable on a /6 is a piece of cake.

Take off the timing cover.
Loosen the anchor bolt down there on the engine front for the tach cable.
Unscrew the tach cable collar from the tach instrument.
Thread in the new cable and secure in the reverse of what you just did. Lightly grease both ends as you put them on.
Put the timing cover back on ensuring the points cavity is properly sealed and the tach cable grommet is cleanly secured between the timing chest and the cover.
If the tach bounces around it is because the instrument needs a rebuild; basically the drive/worm gear at the attachment point of the cable to the instrument.

Teo

/6 must be a wee bit different than my /5 - it was truly physically impossible to get that darn nut on the cable loose without dropping the unit's hold-down plate - that plate that secures the tach/speedo movement to the inside of the bucket. In contrast, the speedo cable is right there in front, just unscrew it effortlessly...

Really, I have the smallest of hands too. Wires were as much of an issue in there (getting to the nut to loosen it) as was the interference with that bracket. If I'd not taken it off I would have ripped half the wires out in the process instead of only a few - simply from wedging my sissy-girl hands up in there!

Glad you have better, easier and more accurate advice for his situation.

Be careful of the rectangular rubber grommet that goes into half of the timing cover and half of the block; it's easily broken if it is hard like mine was while trying to get the old cable out of it and the new one back through it. I heated mine with a heat gun - I still broke it nearly in half like Bakelite. Don't tell anyone I cheated and used a special adhesive to put that grommet back together with no signs of me ever ripping it up...

AHA! Therein lies the difference - your headlight housing. The light goes on in my head. Sorry, I didn;t think past that.

As to the square grommet on the timing cover, you should be a ble to buy a new one and thread it onto the cable if it doesn't come with a new one. I have replaced mine before and I am sure that the grommets for /5 and /6 are alike.

Sorry for the confusion,
Teo

No, no apologies appropriate for me - I was the confused party here...

Yep, my experience was not at all helpful for a unit unlike the older /5 models. I thought just from trying to recall pictures that the instruments and buckets were the same on the /6 for some reason - now I know better. It surely makes sense why they might have made such a change too; not a lot of things for the designers to change when making a new model anyhow and a headlight bucket, well that's one of a very small number of parts they were able to "play with" styling and functionality wise and still have a "/anything" look.

Yes, the grommet will have its day on my bike. While it had hardened beyond reason, the real reason I broke it trying to get it off was it was as if it had been glued on. I'll add a new grommet to this year's "short list." Thanks for clearing that up, I hope I did not confuse the OP; surely was not my intent.

If your old cable is broken you'll know it. One end will turn while the other doesn't. You can simply pull the core out and look at it. A kink in the cable sheath can make a tach bounce a little. If it bounces a lot you've got a problem in the tach itself. The /6 cable is an easy installation. Just make sure you route it so it doesn't kink when the bars are turned.

New cable went in without a hitch on the /6. It was easy and straight forward, but still took 30 minutes, so I am glad I didn't try it on the way out Friday.