Page 1 of 2

electronic rev counter 350 Sport...

Posted: 17 Oct 2021 15:23
by Matt Hale
Hi All- my old electronic rev counter is completely recked- it started with circuit board failure then I tried to fix it and ruined the whole thing !

Do any of you have a spare or know where I can get a replacement? I have been looking for ages...I might be ok with a non Morini one if it was the same OD size- any recommendations? I did find a non Morini Veglia second hand but it only comes alive if I rev very high...maybe there's something I can do about that?
Many thanks in advance for any help!
Matt

Re: electronic rev counter 350 Sport...

Posted: 17 Oct 2021 17:40
by MickeyMoto
Hen's teeth, I'd say.

You can swap for a mechanical one, but the clock is completely different.

I think some early Guzzis had the Vagueliar electronic tachos.

Re: electronic rev counter 350 Sport...

Posted: 18 Oct 2021 02:24
by Mepstein
A friend of mine buys a modern generic tach and moves the new "guts" into the old housing with the original face and needle. He's done a couple and it seems to work well. Not much to loose trying if your old one is non functional.

Re: electronic rev counter 350 Sport...

Posted: 18 Oct 2021 09:01
by Matt Hale
Hi -Thanks for these possibilities- both good- how do you change to mechanical?- Would I need to buy a new engine case or something? There are lots of mechanical Kanguro Tachos available not sure how to use them...mecahnical more reliable and less fragile then electronic probably?
thanks again
Matt

Re: electronic rev counter 350 Sport...

Posted: 18 Oct 2021 10:53
by MickeyMoto
Hi Matt,

You need a new cover eg https://www.ebay.co.uk/itm/273928922688 ... SwTFRdKy9E (but not at that price!)

the 90 degree bend thing and a nut with a square to go on to the camshaft.

Or

https://www.mdinaitalia.co.uk/M460306U.html

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 10:33
by BumbleBee
Just a thought. The model of electronic tacho on Morinis are very specific to Morinis because of the firing interval, if yours is totally wrecked it may be best /easiest to have it professionally repaired. Other people have had top quality service from professional repairers such as Peter Bond ( guageman1@gmail.com ) He's probably the best (and costs reflect this) but versus the cost of finding a mechanical one, and cable, and camshaft end drive bits and other small bits and whether it's face will match the speedo...
If it's not totally wrecked that's another matter, but if you reckon it is.

G&A

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 12:30
by MickeyMoto
BumbleBee wrote: ↑26 Oct 2021 10:33 Just a thought. The model of electronic tacho on Morinis are very specific to Morinis because of the firing interval,

G&A
That's interesting. I always thought that the transducer would control the tacho. Not sure if this is every stroke or every other stroke on that particular cylinder.

I would be interested to see how it works. It can't be a difficult circuit, bearing in mind it was designed in the 70s. No microchips! :)

Mike.

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 15:51
by lemans
BumbleBee wrote: ↑26 Oct 2021 10:33 Just a thought. The model of electronic tacho on Morinis are very specific to Morinis because of the firing interval,
G&A
no, not really.
there one grey wire from a transducer to the tacho, so its one pulse every 720 degrees, 2 crankshaft rotations

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 16:24
by BumbleBee
Mike,
Someone was ahead of their time, there's definitely something like a chip in there :-)
About the pulses. To get the right rpm displayed, from the available signal., it's not that simple, although we all wish it was. It's maybe not about the firing interval it's maybe something else.
Heehee don't ask us any more details we'll need to go and consult a grown up :-)

G&A

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 19:22
by MickeyMoto
BumbleBee wrote: ↑26 Oct 2021 16:24 Mike,
Someone was ahead of their time, there's definitely something like a chip in there :-)
About the pulses. To get the right rpm displayed, from the available signal., it's not that simple, although we all wish it was. It's maybe not about the firing interval it's maybe something else.
Heehee don't ask us any more details we'll need to go and consult a grown up :-)

G&A
Does it use PFM technology?

Re: electronic rev counter 350 Sport...

Posted: 26 Oct 2021 21:22
by BumbleBee
Oh purely :-D
Isn't that how all manufacturers explain their kit :-D

G&A

Re: electronic rev counter 350 Sport...

Posted: 27 Oct 2021 05:51
by Ming
I think somewhere in my archive I have a circuit for the driver - the tachometer is just a meter I’ll see if I can find it.

Re: electronic rev counter 350 Sport...

Posted: 27 Oct 2021 06:49
by MickeyMoto
Found this... May be worth checking it isn't a simple mechanical fault first.

https://wildguzzi.com/forum/index.php?topic=86108.0

Re: electronic rev counter 350 Sport...

Posted: 27 Oct 2021 08:36
by huub
i had a friend fit another printed circuit board in a morini rev counter , because he could not find the original semiconductor so could not repair the original PCB.
apparently it is a simple device converting pulses to a raising voltage.
but the internals of any rev counter ( for a single ) should work

Re: electronic rev counter 350 Sport...

Posted: 27 Oct 2021 09:24
by lemans
http://www.loutrel.org/Veglia.html

schematics of the rev-counter