Tachometer

[TSoftware 15]

I am in the process of doing an engine swap from a 532 to a 582.  I have noticed that the current tachometer, which appeared to be working fine, was wired directly into the charging circuit in parallel with the regulator.  I am reasonably sure that this should work equally well with the 582, but thought I would check with those with more experience than I.  I have seen that many people are using a tiny tach, but my concern is that it is only measuring a single mag, so of course measuring mag drops would not be possible.  Any thoughts?

[akflyer 1427]

you wrap the lead around 2 of the pug wires so you can measure the mag drop on the tiny tach.  If you have an analog tach the chances that its ready way off are VERY high.  I have seen them from a couple hundred RPM off to over 1000 RPM off.

 

[TSoftware 15]

Just so that I am clear, you are saying to wrap the one sensor wire around two of the plug wires?  I only ask for this clarification, because the Tiny Tach that I am looking at, specifically the TT2A, only has one sensor wire and of course, they show it being wrapped around a single plug wire.

[1avidflyer 1983]

I think most people's ears are good enough that they could tell that they had a bad ignition without looking at the tach.  Flown several 2 strokes with a Tiny tach that just read one side.  Another thing, most 532s had points ignition, while the 582 had electronic ignition.  532 makes one spark per rev, 582 makes 2 sparks per rev.  There for, a different tach is required for each engine.  JImChuk

[TSoftware 15]

Yes, the 532 had a points ignition, but was thinking since this tach was pulling from the charging circuit that it would be right

[1avidflyer 1983]

Yes, the 532 had a points ignition, but was thinking since this tach was pulling from the charging circuit that it would be right

Not according to my memory.  I switched from a 532 to a 582 on my first Avid and think I had to change out the westach tach.  But then again, my dad got alshimers.  Might run in the family.  JImChuk

[EDMO 1078]

I bought an imitation Tiny Tach with a replaceable battery - Donno how good it will be, but for $14, I don't have much invested.   EDMO

[Dusty 126]

Ears are a better judge of mag drop on a 582 than a tach.The tiny tach's are so cheap and light,try one per ignition so an in flight ignition failure can be picked up when/if it happens

[TSoftware 15]

I don't doubt that and I happen to think that is true on my certified aircraft as well.  However, when I have to get a condition inspection, I am guessing that the mechanic is going to want to see a more concrete representation.

[TSoftware 15]

For the 582, what version of the Tiny Tach is everyone suggesting?  The TT2A?  I have seen on other posts that people were setting this to 180 (2 sparks per revolution) for the 582, is this the correct setting?  JimChuck, I now that is what you have already said....but am getting ready to order and want to make sure that I order the correct model and set it up appropriately.

TIA

[akflyer 1427]

yes I wrapped the lead on the tiny tach around both plug wires going to one cylinder.  This will give you the mag drop.  Make sure you get a good 5 or 6 turns around the wires.