Rev Counters

[tjc]

I wish to fit a rev counter. The engine is Volvo MD7 fitted with an alternator.

Is it easy, if so any tips on wiring. Where is the "W" terminal?

Secondly the Volvo one seems rather expensive to say the least, any ideas on where to get a cheaper alternative.

Thanks in advance

 

[Guest]

Yes, easy to fit, "w" terminal is on back of alternator, marked "w", not all alternators seem to have them, specially old ones, but I'm no expert on that. Try www.lancingmarine.com or vetus.co.uk. I couldn't find cheap ones but Volvo has a reputation for high prices.

 

[neale]

I just re-instrumented (is that a real word?) my whole dash using Faria guages supplied by ASAP. Very reasonably priced.

Neale

 

[andyball]

I second that....asap'll sell you a faria tacho' for £55 ....is that cheaper than Volvo?.

http://www.asap-supplies.com and follow the guages/electrical....then the left hand faria link.

 

[PGD]

Hi, I've got a second hand one if you are interested, came off my old VP Aq175A V6 got some setting oon the back to adjust it, any good to you?

Peter

 

[peixe]

Penman Severn Consultants, 01452 750286, www.cgauge.com, do a neat encapsulated solid state combined tacho and hour-meter for £75. Have just fitted one in the cockpit (it is completely impervious to weather) and it works fine. Easy to fit.

 

[scottie]

petrol tach no use for md7

 

[tadpole]

how do you know which one?

I thought all rev counters were different. What is the right type for a Beta 13.5hp twin (theirs is too expensive for us) Mechanical or electrical. How do you connect it. Excuse my ignorance.
Cheers,
Steve

 

[andyball]

Re: how do you know which one?

I know little about diesels.....but it seems you can buy elcectrically operated rev counters to be driven from either the alternator/dynamo OR from a magnetic pickup. "Alternator sensed tacho's are easily calibrated to suit most engines"...they say.
Faria also sell a "sender" unit...that "...attaches to the mechanical take off".

Doubtless there are purely mechanical ones too .

 

[dick_james]

If you don't have a 'W' terminal on the back of the alternator you can easily make your own connection by removing the back cover of the alt. and soldering a wire to one of the field windings where it conects into the diode array (ie. before the diode). Some rev counters come with instructions on how to do this anyway. It's easier than it sounds.
Dick James