Author Topic: tacho rotation  (Read 477 times)

Offline yar

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tacho rotation
« on: 14.11. 2017 07:49 »
 Hi every body   Help please
 I know this is an old topic as such. But I really  need to know about my A10 oil pump drive for the tacho  or in my case the lack of it .
  As I am about to order parts to get my dummy tacho working . I am aware that it is supposed to have a RC 1303/03 Tacho and that it is a 3/1 reverse/counter drive but looking at pictures of the dial the needle is obviously going to travel around clockwise.  So looking from the back does this mean the drive is actually counter clockwise
 Or did the original  mechanisms inside  reverse the drive. So looking at the drive on the pump from the front is that traveling counter or clockwise ?
 I can get a reproduction clockwise or anti but the repro anti has a dial that travels  anti clockwise so am assuming that it  is a simple magnet drive and would require  looking at it from the back, a clockwise drive so if the pump is driving anti  it would be wrong    Ha ha
 Having put this into words I am still confused has any body purchased and fitted a reproduction Tacho for the oil pump drive on the A10  as I need to make sure I get the correct dial for the pump type direction of drive looking at it from the front
 Many thanks if you can help   
Bike Tragic

Online chaterlea25

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Re: tacho rotation
« Reply #1 on: 14.11. 2017 12:16 »
Hi,
Quote
Or did the original  mechanisms inside  reverse the drive.

Yes they did
It maybe possible to fit a reverser in a custom drive cable ??

John
1961 Super Rocket
1963 RGS (ongoing)

Offline kiwipom

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Re: tacho rotation
« Reply #2 on: 15.11. 2017 02:52 »
Hi Yar, I had more or less the same prob as you. I used a Triumph taco and had it fitted with a new face and recalibrated to 3-1. It reads the other way to normal bsa taco but it works o.k, it was quite an expensive operation, cheers
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

War! what is it good for?Absolutely nothing, Edwin Star.
NewZealand

Online Bsareg

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Re: tacho rotation
« Reply #3 on: 15.11. 2017 09:47 »
Had a similar problem with rev counter on my 59 RE Fury . Dismantled an old chronometric speedo,  skewed the mechanism to one side,  mounted a gear off the redundant odometer as a intermediate gear, new face and recalibrate,  job done. Been running fine for 20yrs.
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online edboy

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Re: tacho rotation
« Reply #4 on: 15.11. 2017 19:14 »
i wonder if a65 oil drive gears will work. the a65 had a 3/1 tacho . any experts?

Offline kiwipom

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Re: tacho rotation
« Reply #5 on: 15.11. 2017 19:36 »
hi guys, yes but as far as i know the A65 pump rotated in the opposite direction, cheers
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

War! what is it good for?Absolutely nothing, Edwin Star.
NewZealand

Online JulianS

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Re: tacho rotation
« Reply #6 on: 15.11. 2017 19:50 »
A65 pump rotates in the same direction as A10 but the drive worm and crank worm are cut opposite to A10 because it is driven on the pump gears furthest from the crank face. A10 driven on gear nearest crankcase face.

So A65 gears would rotate A10 pump the wrong way.

Offline kiwipom

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Re: tacho rotation
« Reply #7 on: 16.11. 2017 00:50 »
Had a similar problem with rev counter on my 59 RE Fury . Dismantled an old chronometric speedo,  skewed the mechanism to one side,  mounted a gear off the redundant odometer as a intermediate gear, new face and recalibrate,  job done. Been running fine for 20yrs.
hi, Bsareg, can you detail that work that you did to make a rev counter from a speedo, i have got a couple of chrono speedos kicking around that i could do that to, cheers
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

War! what is it good for?Absolutely nothing, Edwin Star.
NewZealand

Online Bsareg

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Re: tacho rotation
« Reply #8 on: 16.11. 2017 09:58 »
After 20yrs can't remember the measurements, but will whip tacho off bike and check inside at weekend
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online Bsareg

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Re: tacho rotation
« Reply #9 on: 19.11. 2017 17:47 »
Removed the reversed tacho from bike but another twenty years and my decrepitude has meant I am unable to remove bezel without destroying it. Will have to rely on my memory???  Remove front, needle, face, and main casting. Remove main mech and odometer keeping odometer drive pinion and screw. Swivel main mech to one side ( keeping needle spindle central ) until there enough room to engage redundant odometer  pinion between rocking pinion and drive pinion. Mark out the three new holes remembering that you need to tap the odometer screw hole. Lightly oil and assemble.  Calibration is by adding/removing weight to the escapement wheel, more weight = higher reading,  less weight = lower. Difficult to describe but hopefully you get the gist 
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA