Jumping Tachometer Needle

charles.walmsley · Post by **charles.walmsley** » Sun Jan 07, 2018 10:04 am

Ive noticed that the tac needle for my 75 R90S starts to jump heaps once I get to around 3000 revs. When I say the needle jumps im talking from one end of the tac to the other. Bumps on the road make it worse but even on flat surfaces it does the same thing. Could it be just a worn out speedo cable or something else?

schrader7032 · Post by **schrader7032** » Sun Jan 07, 2018 10:09 am

I would definitely change the tachometer cable. I'd also not ride the bike anymore or at least disconnect the cable until this is fixed. Eventually the tach side will be damaged and your repair bill jumps quite a bit.

MikeL46 · Post by **MikeL46** » Sun Jan 07, 2018 10:30 am

Have you lubricated the cable? And not with oil.

Mike

charles.walmsley · Post by **charles.walmsley** » Sun Jan 07, 2018 6:31 pm

I havent done anything yet but I might try lubricating the cable first. Is it best to use a spray like inox or WD-40?

schrader7032 · Post by **schrader7032** » Sun Jan 07, 2018 6:48 pm

Don't use WD-40...it's a dirt-attracter. Best to use something like Tri-Flow.

MikeL46 · Post by **MikeL46** » Sun Jan 07, 2018 7:28 pm

I would use a graphite lubricant. Oils and greases attract dust and gum up. Just like on key locks. Oils and greases are great for control cables (clutch, brake, throttle) but not for speedo/tach cables that rotate at fairly high rates.

Pull the inner cable out and shoot the graphite in then reinstall the inner.

Mike

brownbmw · Post by **brownbmw** » Tue Jan 09, 2018 11:48 am

No need to lube these cables. If that is the cause of the needle fluctuation then it is either kinked or has a broken wire strand and needs to be replaced. If it's not the cable then there's a problem in the tach.
Since "bumps on the road make it worse" it is very unlikely that the cable is the issue.

charles.walmsley · Post by **charles.walmsley** » Sat Jan 20, 2018 6:09 am

Have been on holidays so I will have a look at it soon. Thanks heaps fellas

charles.walmsley · Post by **charles.walmsley** » Thu Jan 25, 2018 8:07 am

What are the steps in order to remove the cable to inspect and possibly lubricate?

Vintage BMW Motorcycle Owners

Jumping Tachometer Needle

Jumping Tachometer Needle

I would definitely change the

Have you lubricated the

I havent done anything yet

Don't use WD-40...it's a

I would use a graphite

No need to lube these cables.

Have been on holidays so I

Process