Tachometer rev counter issue.

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fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Tachometer rev counter issue.

Post by fatnfast »

Can the electronic tacho be overhauled or is there a modern equivalent that could be adapted?
It seems mine is a little iffy.
I did do some searching but couldn't find any information sadly.
Cheers all ,
Phil.
lambs
Posts: 27
Joined: 18 Jan 2017 23:22
Location: Melbourne, Australia

Re: Tachometer rev counter issue.

Post by lambs »

NLM have a 'rebuild' service and use a guy who is an ex-RAF technician (well, so they claim, but there's no reason to suspect anything different).....sent you a PM about that.

The mechanicals seem to be similar across Veglia electronic tachs of the period. Some early Moto Guzzi V7's used an electronic tach that, as far as I can tell, is identical to the Morini item (apart from the dial face, of course). Some Italian cars also used a Veglia electronic tach. A firm specialising in instrument rebuilds (preferably Veglia's) should be able to help with the mechanicals....see above.

In terms of improving/replacing the drive electronics, this is an interesting site:

http://www.dinoplex.org/tachoconversion/

I don't claim to be an expert, but I've done a few electronics projects over the years and this looks pretty straight forward. Probably use a bit of veroboard to do a 'prototype'. Can't see any reason why it wouldn't work. One thing to note is that the electronics is 'designed' for 4/6/8 cylinder engines but it looks to be a case of experimenting with the value of one resistor to make it work with a 2 cyl engine.
1974 Moto Morini 3 1/2 Sport
1972 Moto Guzzi V7 Sport
1975 Moto Guzzi 850-T3
1976 Moto Guzzi 750-S3 (owned since new)
1978 Moto Guzzi 850 Le Mans Series 2
1983 BMW K100
1983 BMW K100RS

1974 260Z
1989 R32 GTR
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

Thanks Lambs, the info is much appreciated. I have also PM'd you back.
Db7gtgrigio
Posts: 80
Joined: 16 Dec 2015 09:01
Location: Sydney, Australia

Re: Tachometer rev counter issue.

Post by Db7gtgrigio »

same tacho inards in the Ferrari Dino......
lambs
Posts: 27
Joined: 18 Jan 2017 23:22
Location: Melbourne, Australia

Re: Tachometer rev counter issue.

Post by lambs »

It's amazing what you can find on the internets......this is a link to a discussion on a Morini enthusiast site in Italy where the OP has built a complete replacement for the innards of a 1976 Sport tach using a 3D printer, a stepper motor for needle drive + associated electronics:

http://www.morinispecial.it/joomla/foru ... da-te.html

I used Google translate, which is good enough to get the gist of it.

An impressive effort to put it mildly.
1974 Moto Morini 3 1/2 Sport
1972 Moto Guzzi V7 Sport
1975 Moto Guzzi 850-T3
1976 Moto Guzzi 750-S3 (owned since new)
1978 Moto Guzzi 850 Le Mans Series 2
1983 BMW K100
1983 BMW K100RS

1974 260Z
1989 R32 GTR
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

That's very good indeed and a great mix of the 1970s and modern day technology. It would be nice to know the exact circuit diagram for that.
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Paz2112
Posts: 126
Joined: 07 May 2015 12:32
Location: Northern Ireland
Location: Northern Ireland

Re: Tachometer rev counter issue.

Post by Paz2112 »

I had my clocks totally overhauled by Andy Barraclough at Speedy Cables. I can only say that they came back as new and work perfectly.

Image
My Other Italian V-Twin is an Italian V-Twin
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

Thanks again Paz. Can I ask if they repaired your tacho or was it already working and just needed restoring?
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Paz2112
Posts: 126
Joined: 07 May 2015 12:32
Location: Northern Ireland
Location: Northern Ireland

Re: Tachometer rev counter issue.

Post by Paz2112 »

It was working but in very bad repair. The needle was warped and the face faded. At the same time I got them to replace the innards of the Speedo and convert it to MPH from KPH using brass cogs. A great job all round.
My Other Italian V-Twin is an Italian V-Twin
pedro
Posts: 311
Joined: 04 Nov 2010 21:14

Re: Tachometer rev counter issue.

Post by pedro »

I have recently had a tacho done by Speedy cables, not such a positive outcome.
Firstly they were anything but speedy, four months in total, secondly they were VERY expensive,they did a lot more work than I asked them to do and charged me for it. Thirdly, when I eventually got it back they had not done what I sent it to them to do in the first place but done a lot of unasked for work instead. To be fair Andy was horrified when he read my original letter that I sent in with the tacho, I had to send it back, which cost me another tenner for them to put right. They wouldn't move on price or give me my postage back for having to return it. They did turn it around in a week the second time though. I will not be using them again, I felt well and truly ripped off.
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

Good and bad experiences then.
I may have solved my non-working tacho as I finally took delivery of the bike yesterday. It has the later transducers (as per the Dutch site) which means no output for the tacho? :evil:
So maybe my tacho is fine. I don't really want to buy new transducers from NLM (££££££££!!) just to see if the tacho will work, so will have to think up another way of providing the pulsed supply. Any ideas?
JonD
Posts: 37
Joined: 14 Jan 2014 10:40
Location: Wantage

Re: Tachometer rev counter issue.

Post by JonD »

Look at Soren Hansen's u tube video on Morini ignition system part 3 and you will find two circuits to drive the electronic tachometer.
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

Thanks Jon for the link. I have emailed Wolfgang Tritsch as Soren says he does ready built tacho drivers. I fitted a new light switch today so double checked the transducers. They are the later grey type.
Papa Lazarou
Posts: 156
Joined: 10 Nov 2016 09:42
Location: Sussex

Re: Tachometer rev counter issue.

Post by Papa Lazarou »

Since the NLM coils and box have been installed, my tacho reads double revs. WTF?
fatnfast
Posts: 59
Joined: 31 Jan 2017 15:55
Location: Kent UK
Location: South East, UK

Re: Tachometer rev counter issue.

Post by fatnfast »

Give NLM a ring, at least you have a rev counter that works :(
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