582 Tacho

Re: 582 Tacho

by Damien Gates » 14 years ago

Damien Gates

3 22 17

Thanks all,

Yes Bill, having substituted a new ground for the tach with no change, checked the (brown) ground at the engine and the Reg/Rect seems OK, unless I have missed something (still highly likely...) then it must be the tach or greywire / resistor.

What readings should I get from the grey wire AT THE TACH at different RPM?... this should isolate the grey wire resistor as the problem, if it is correct it must be the tach. The new tach is some weeks away, no doubt I will sort this problem out one day before it arrives :blink:

Re: 582 Tacho

by bill martin » 14 years ago

bill martin

10 757 0

The tach wire counts pulses as the rotating magnets go by the coil it is hooked to. I don't really know how to check it except for continuity. Roger or Richard can probably answer that one for you. If you do have to change it, it's a fairly easy job to do. the worst part is getting to it in some installations. The coil it is hooked to is obviously OK if the engine runs, which gets you back to the tach or the grey wire. You may or may not have an internal resistor depending on the age of the engine. In either case, its an easy fix if thats the problem.

Bill

Re: 582 Tacho

by Richard Jowsey » 14 years ago

Richard Jowsey

0 10 0

I know the tach needs about 3-4 volts AC at the gauge ... less than that, some of them appear to mis-read the pulse frequency (like mine did, until I added a mid-point tap on the charging coil, which delivers 10-15 volts). If you're measuring (say) 10 or more volts at the tacho, it should be accurate. If not, the tach is munted, or there's perhaps a problem with some inline resistor.

Hope that helps
Richard

Re: 582 Tacho

by Damien Gates » 14 years ago

Damien Gates

3 22 17

Thanks, Engine is quite old so perhaps the resistor... will check voltage for 10 or better at the tach

Re: 582 Tacho

by Damien Gates » 14 years ago

Damien Gates

3 22 17

Hi All,

Just thought I should follow up on this and thank you again for assistance. We think the problem was in the stator somewhere but I managed to track down a bit more of this engines history 2330hrs total and 400hrs+ TSO... while compression and bearing test were good various other things were obviously in need of immediate replacement (carb floats, oil lines and more).

New engine installed and I actually put in a Tiny Tach with that so I could panel mount a new radio where the old tacho was.

Cheers!