Speedo flickering

rexeriot · Post by **rexeriot** » Fri Aug 08, 2014 4:58 pm

Hi Exup Gods

I had a speedo that flickered very bad .At low revs it was fine but so as the revs went up the needle would go wild and only settle down when the revs go down. Ive changed the speedo and its still doing the same. The speedo drive and cable have since been changed but the speedo still is very erratic. One second its fine but the next the needle is going mad....any ideas . Thanks.

YAMAEXUP · Post by **YAMAEXUP** » Sat Aug 09, 2014 10:22 am

Could it be because of vibration??

Are the clocks solidly mounted??

Post by **Stig** » Sat Aug 09, 2014 11:07 am

were the replacement items KNOWN to be good?

Post by **nugget** » Sat Aug 09, 2014 11:19 am

I've got the same problem with mine. I've checked the speedo drive at the wheel all ok there. I've fitted a brand new speedo cable. (Not a genuine Yamaha one I must state) The speedo needle is ok until I go over 80 then it's anybody's guess what speed I'm doing. I'm starting to think if it's the gearing cogs in the actual clocks that are wearing out about a bit?

My next option is to buy some more clocks to see if that cures it.

rexeriot · Post by **rexeriot** » Sat Aug 09, 2014 11:29 am

Thanks for the replys. I was thinking vibrations but the clocks are mounted securely and when the needle starts to go hay wire there is no movements in the housing whatsoever. Thought it was related to bike revs but its so random. Ill be riding at a constant speed and the needle will be fine , then it goes wild and then settles again. I can only think its the clock itself but this is the second one ive fitted and does exactly the same as the first. Maybe its a fault they develop when the get old. Its very annoying as it would be nice to know what speed im doing all the time.

Pitbull · Post by **Pitbull** » Sat Aug 09, 2014 11:48 am

Just an idea, take the wheel off, and clean the speedo drive and add plenty of fresh grease and add more grease when you put in the cable on both ends,

Post by **nugget** » Sat Aug 09, 2014 11:58 am

Done all that my good man and it's still the same.

banner001 · Post by **banner001** » Mon Aug 11, 2014 4:40 pm

ive not taken my old stock speedometer apart (but i might tonight), but this is now most mechanical car speedometers work (i expect the bike to be the same).

your speedometer cable is connected via a small plastic gear to a magnet (magnet 1). as you go faster and faster this magnet spins faster and faster. around the outside of this magnet is another circular magnet (magnet 2), but its held back by a spring and can only turn so far - this is what your speedometer needle is connected to. as you pick up speed magnet 1 spins, this causes magnet 2 to try and spin...but its held back by the spring, as you go faster and faster you generate a larger force between magnet 1 and magnet 2 and this rotates your speedometer needle further round.

if its acting erratically its either a damaged speedometer cable, one of the speedometer magnets loosing its magnetism, or damage/play in the spring.

hope that helps.

yzfpaul · Post by **yzfpaul** » Mon Aug 11, 2014 9:23 pm

if banner takes his speedo apart he'll agree with my tupenceworth
almost always with the yam speedo's its the green cog that wears out
if you are mechanically minded and have a rivet gun you can change the cog
but you would need to use a cog from another speedo as this part is not sold
seperately.

i have a good working speedo if you and nugget agree to post it to eachother as a tester then i'll send it for you both to try.

Post by **nugget** » Tue Aug 12, 2014 10:28 am

Thanks for the offer Paul. Im not in a big rush to start taking the speedo clocks to bits. Anyway I'd probably lose all the springs and clogs and whatever else that'll come flying out of it.

Roadrunner has a spare set of clocks, so I may stick them on as a tester and take it from there.

Thanks again.

banner001 · Post by **banner001** » Tue Aug 12, 2014 3:07 pm

yzfpaul wrote:almost always with the yam speedo's its the green cog that wears out

but you would need to use a cog from another speedo as this part is not sold
seperately.

if the green cog is part of the assembly that attaches to the back of the speedometer it is available, but might be pricey - 4FM8352000

i didnt have time to take mine apart yesterday, i was too busy repairing my full carbon zxr400 exhaust back to mint condition

IMG_20140812_135412787 by johnduncan2000, on Flickr

yzfpaul · Post by **yzfpaul** » Tue Aug 12, 2014 3:39 pm

i love shiney things

nope thats not the part banner i'll take a pic of it when i get home tonight

rexeriot · Post by **rexeriot** » Sun Aug 24, 2014 7:47 pm

Have now fitted my third speedo head and greased the speedo cable. For the first 10 miles the flickering was minimal. By mile 40 it was flickering like a goodun. My synopsis is that the speedo internals are delicate , wear quickly and becomes susceptible to any vibration or jerking easily. My other bike is a ZRX1100 which has an instrument panel that vibrates a lot but my speedo , and the bike is 16years old and I've had it from new , never misses a beat. On my Exup with an instrument that doesn't vibrate , the speedo goes hay wire. Is it to do with the routing of the speedo cable , going in from the side ? Possibly. By lubing it it works better but not for long. The cable is obviously rubbing against the outer casing at some point and due to the angles it has to go I'm not surprised. I'll get a new cable but know it's not going to be perfect all the time the speedo is so sensitive to vibrations. Every time over a bump the needle wobbles and that has happened to 3 speedos now. Any ideas what I can do is welcome chaps....thanks.

rexeriot · Post by **rexeriot** » Sun Sep 07, 2014 8:04 pm

Have now fitted a news cable. First ride it worked fine, no flickering , for the first 20 miles then slight flickering started and slowly got worse but not as bad as before. Left the bike for a day. Took her out and no flickering again until after about 20 miles then the same. Something is obviously getting hot and causing the flickering after a certain amount of time. Any ideas ? Is maybe the inner cable vibrating against the out cable due to the angles the cable has to go ?