Help, NSR125 Broken Speedo!!!

[John C]

HELP!!! My NSR125’s speedo’s completely packed up.

It never gets above 20 and wobbles. I took the cable off the wheel, and spun it with a screwdriver attachment on the drill. The clock read 40mph constant, so I can rule out the cable and the clocks.

I took the wheel off, and removed the bit which spins the speedo cable. The teeth on the gears where fine, the bushes fine, there was no play, and the teeth where not jumping.

However, I can’t see for the life of me how the spinning wheel turns the gear. And when I refitted the wheel, I found that when I spun the wheel the bit that drives the cable could be stopped with very little effort, leaving the wheel the wheel to spin.

So I think the problem is that when the wheel spins, the gear which drives the Speedo cable does not spin with it.

Has anybody got ant clues as to why this is happening, as I am stumped?

Thankyou

[alains]

i think your problem comes from the washers (9) . those cost peanuts , but the whole gear(7) cost £60-70 . have a carefull look on that otherwise i suggest you find a breaker if the gear needs to be changed
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the worst day fishing is better than the best day working

[John C]

Thanks,

is that diagram from www.nsr125.com?

I have the outer case (7). Then 1 flat metal washer (9) [not 2] then gear number 8, then on top of that there is number 13.

I can't see any rubbers, nor can I see how the wheel turns number 13???

[alains]

number 13 is the seal beetween the wheele bearing and the speedo system . friend of mine had this problem recently and it was the washers . this picture comes from the microfiches (sorry, in french) , you can download from my ftp
https://www.geneva-racing.com/~limp/nsr/NSR125refs.zip
when you unzip you will get 4 files in wordXP , look the partiecycle.doc . most of the refs are the same in france & uk
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the worst day fishing is better than the best day working

[John C]

I seem to have all the bits, and can see how number 13 turns the gear, but how does the wheel turn number 13

[alains]

no , try to change the washers . ask tim https://www.davidsilverspares.co.uk
ph : 01728 833 020
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the worst day fishing is better than the best day working

[John C]

Tried to phone but always engaged???

What washers.????

I only have the case, 1 metal washer, the gear, and the seal with the 2 tangs on it which fits over the gear?????

Arhhh, confused

[John C]

AND WHY ARE THERE 2 PART 9's IN THE SCHEMATIC???

[alains]

i think they are friction washer . try tim to-morrow at 9 :am
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the worst day fishing is better than the best day working

[John C]

SORTED.

I took it all to pieces agin, and cleaned out all the grease.

I found that I did have 2 part 9's.

Also I found that part 13 was rubber on the outside, so instead of fitting it into the Speedo drive, and then putting the whole lot on the wheel, I carefully drove part 13 into the wheel using a flat piece of wood and a rubber mallet. It's seems its just the tight fit which make 13 spin with the wheel.

JUST one question.

If you hold a bearing in you hand, does the rubber spin with the inner or outer metal cylinder?