revcounter /tacho

[vicar]

Hi
my etz 251 has a powerdynamo fitted and the electronic tacho wont work, can I convert it to a cable driven tacho if so what parts do I need and has any one got the bits for sale....................
The bikes been fitted with an 18inch wheel with a 120 /90/18 tyre and the std speedo is miles out (16 inch std) I need a speedo from a bike with an 18 inch wheel as std so it looks like I need a revcounter and matching speedo with brackets .........I am new to this forum but the bikes not steve 1200s was making a cafe racer out of it it had been a mini bmw gs look a like before he got it .I just want to get it back on the road as a bike to use. Vicar

[Trogolodyte]

The electronic ignition from the power dynamo system should still feed to the main coil as per any other Mz system, the green wire that the old system uses to feed the electrical pulses from the dynamo/alternator to the tachometer might not be there but if you use the feed into the main ignition coil (not the HT lead!!) you will get the same electrical pulses the that kanuni /late ETZ fun/tour even the 500's did use the same system, all you should need to do is run a wire through the loom from the coil feed to the to the rev counter or even use the green wire if you still have it in your loom.... simples, I think this would work as all the "green" wire on my 500 country did was send the low power ignition pulse signel (before it went through the coils and induced The Ht spark pulse) to the tachometer which then used it to display rpm's, please correct me if I am wrong

[vicar]

The paperwork from powerdynamo is clear that the the electronic tacho will not work or be adapted to work with their system.

which is why I want to go down the retro rout and return to a mechanical system if it can be done any one got any ideas.and parts.........Vic

[radiograf]

To fit a mechanical tacho you will need:
the tacho drive nut on the left hand end of the crank,
a tacho drive assembly, to fit on the left side in place of the blanking plate,
tacho cable.
round type tacho, rubber boot , and bracket.
The parts usually available on ebay, if not today, try tomorrow.
The speedo you will need has to come from an ETZ250, as this is the model with an 18" back wheel

[Skorpion]

I think you will find that you will only need the speedo worm drive, from a ETZ 250, that fits into the rear plastic sprocket cover, to make your speedo correct, not a new speedo.

[vicar]

Thanks for the advice, I will go for the speedo change , because of the revcounter . I will have a look on ebay .Vic