Triumphrat

2008superduke

Hey guys thought I would post this for anyone thinking about replacing the stator. I tested the wire connector with a multi-meter on all prongs to ground and there was no resistance. So off came the cover and yep burnt. So I have a Rick's stator on the way from fleebay and a new gasket from bikebandit.com. I will do another video mounting it.

Maxacon600

Silicone the wires coming out the top. I've still got oil leaking out of that black "seal" that I thought was ok.

__________________
"All of these... moments... will be lost, in time... like... tears... in the rain..." - Blade Runner

DEcosse

Are you saying there was ZERO resistance, or you could not measure any resistance i.e. it was open circuit?
So - short or open, which was it, can you clarify?

Unfortunately there is no great shot in decent lighting to tell whether it is truly burned or not - clearly that section has been getting hot, which is typical as there is less oil cooling in that zone.
If it was indeed short to the case (you can still measure to the core, even when removed) then yes, it would indeed be bad.
But if open, I am not totally convinced that one is a goner.
Did you do the voltage test before you removed it? (although again, if you had a short to engine case, kinda moot)

__________________

2008superduke

DEcosse thank you for your post, I think of you as the expert on these electrical matter. I'm just learning, so here goes: when I measured any of the three prongs to the ground with my multi-meter I got O.L. So I guess that is an open circuit? I would imagine that it should of had some resistance? 0.02 or so? or maybe not

DEcosse

That is the correct reading - the windings should be isolated (i.e. infinite resistance or open circuit) from the core.
You will however measure a low resistance (less than 1 ohm) between each of the three pins to each other. But that is not what we are looking for in failure diagnostics.
Although the wire looks like bare copper, it in fact has a clear insulating sleeve over it.

When the actual windings fail it has burned through the insulating sleeve on the wire and shorts to adjacent turns or directly to the core.
So what we are testing for is the integrity of the insulation, rather than that of the actual conductor.

Yours certainly looks black because it has been hot in that zone and the lacquer discolours; (I think that is what you are seeing burned as opposed to the wire's insulating sleeve) but that one is probably not actually fried to failure.
This is one fundamental reason they fail, is because of the poor cooling in that region and why the fours seem to have disproportionately higher stator failure than other Triumphs. A new one will ultimately look similarly.

My recommended diagnostics for stator are quite simple:

Measure resistance (isolation) between stator output pins and engine ground
a) If short, stator is definitely bad - proceed to remove cover to validate - no need for test c.
b) If open, good indication that stator is OK and proceed to test c to validate
c) Start bike with R/R disconnected, measure the AC Volts between the three combinations of pairs of pins
1-2
2-3
3-1
All three should be very close at any given engine rpm. Idle is usually sufficient to see a problem, although if failed, a larger difference will be apparent at higher rpm.
When failed, a significantly lower voltage will be evident on one phase vs the other two.

If it passes first the isolation test and then the voltage test (all three phases show the same voltage output at any given engine rpm) then the stator is good and I would not proceed to remove the cover - you will just scare yourself with how it looks!

__________________

ramenboy...

Nice vid, suoerduke. I just did this on the speed four a couple weeks ago. You're right, the bolt next to the coolant hose was a pretty tight fit, still was able to the cover on and off.