Strange tacho running

RoadMyster · May 1, 2013

Hello all,
I am a beginer in this magic, unbeleivable and sometime ununderstandable Norton world!
Understandable, for me, not for you, it is the reason why I am here.

By the way, as Frenchy (nobody's perfect) I ask you, once and for all, you indulgence for mistreatment of your language.

Come to the fact:
Bike has been bought some weeks ago. Tacho was working
After a couple of km it came to show too high rev and works mostly like a fan. Needle does not come back to zero
When I drive it on the table with a drill it works smoothly.
On the bike again, I found now, when I get the nut of the cable loose and I pull the cable gently out of the clock it seems to run well.

All ideas wellcome

Thanks in advance

kommando · May 1, 2013

Sounds like the inner cables too long and is forcing the insides of the tacho to make contact, do not run the bike with the tacho connected until this is sorted.

concours · May 1, 2013

Hello, welcome. You've found the cable too long already, good job. Now, WHY? Is the inner cable bent, elongated? Tacho drive in engine inspect well?

RoadMyster · May 1, 2013

kommando said:
Sounds like the inner cables too long and is forcing the insides of the tacho to make contact, do not run the bike with the tacho connected until this is sorted.

For sure it is removed when riding.

concours said:
Hello, welcome. You've found the cable too long already, good job. Now, WHY? Is the inner cable bent, elongated? Tacho drive in engine inspect well?

Cable too long?
Is there different lenght for sale. Don't see why as this length should never change opposite to cable going to handle bar (hi or European)
Strange to me that it worked well when I bought the bike!?!?
In the meantime I have been advised to shorten a bit the square top end of the cable, what do tpu think?

I did not inspect the tacho drive in the engine. I am not in favor of removing this part as I have heard there is here a "chronical leakage desease" and mine does not leak (here) :wink:

DogT · May 1, 2013

With tacho cable installed in engine fully, check length of inner cable at tacho end. It should not stick out past the tacho end nut when the nut is pulled all the way up. Otherwise it will damage inside of tacho. Fix inner cable or get correct cable. Or cable could be binding. Lube or better get new Venhill Teflon lined cable correct length.

Dave
69S

laurentdom · May 2, 2013

Bonjour and welcome to the best site re: Nortons in the world!

As others told you, it doesn't sound like a tacho but like a cable problem.

Is your cable not squeezed (for instance by the central stand when it is folded) or bent too sharply somewhere preventing it to run smoothly and freely, as it happened to me on my Dominator?

Here is my french e-mail address and phone number if you need more details:

lmhusquin@orange.fr
06 80 20 37 44

Laurent

laurentdom · May 2, 2013

Sorry for my mistake. I didn't notice that it was a tacho (not speedo) problem. So no risk of interference with the central stand!

L.

RoadMyster · May 2, 2013

Thanks everybody for the advises and ideas.

Check the lenght: it is ok, the cable just ends at the upper side of the nut when nut pulled up.
Cable well lub, not so much bended.
I am now wondering if the engine drive does push the cable up when running. I will check soon but not this week end as I will not be at home.
I will keep you up dated if I find something notable.

Laurent,
Thanks for your data, wich region are you from?
Are you a NOC member in France?

Thanks again to everybody

Bernard

DogT · May 2, 2013

Yes, check the drive mechanism. It's kind of a strange paddle arrangement.

Dave
69S

laurentdom · May 2, 2013

Hi Bernard,

Yes I'm a member of the french NOC.

I live in Grenoble.

Laurent Husquin

willy mac · May 3, 2013

DogT said:
With tacho cable installed in engine fully, check length of inner cable at tacho end. It should not stick out past the tacho end nut when the nut is pulled all the way up. Otherwise it will damage inside of tacho. Fix inner cable or get correct cable. Or cable could be binding. Lube or better get new Venhill Teflon lined cable correct length.

Dave
69S

Hi Dave

Just been on the Venhill site and can't find anything relating to speedo cables, is this a cable you bought as separate parts from them and made up yourself?

Mac.

L.A.B. · May 3, 2013

willy mac said:
Just been on the Venhill site and can't find anything relating to speedo cables

http://www.venhill.co.uk/Hoses_&_Cables ... CABLE.html

http://www.venhill.co.uk/Hoses_&_Cables ... CABLE.html

willy mac · May 3, 2013

L.A.B. said:
willy mac said:

Just been on the Venhill site and can't find anything relating to speedo cables

Click to expand...

http://www.venhill.co.uk/Hoses_&_Cables ... CABLE.html

http://www.venhill.co.uk/Hoses_&_Cables ... CABLE.html

Thanks LAB,

I found the speedo cable but it won't be long enough for a JPN and the £37.20 for a cable a few inches longer is a bit much when the standard is only £16.75.

L.A.B. · May 3, 2013

willy mac said:
I found the speedo cable but it won't be long enough for a JPN and the £37.20 for a cable a few inches longer is a bit much when the standard is only £16.75.

If it's for a JPN, then it ought to be a 'standard' cable, even if it is longer and not listed, but I don't think Venhill instrument cables are (teflon) lined anyway?

Strange tacho running

RoadMyster

kommando

concours

RoadMyster

DogT

laurentdom

laurentdom

RoadMyster

DogT

laurentdom

willy mac

L.A.B.

Moderator

willy mac

L.A.B.

Moderator

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