Electrical problems.

Right, where to begin
last week riding to the northwest200 my bike suddenly died doin 70mph 6th gear steady cruising (sv650sk1) I pulled over and heard a squealing sound so I removed the seat to discover my battery smouldering and screaming. No power as battery was dead so couldn't restarts her so got her lifted by a mate n brought home, this is where it gets weird
hooked it up to a good battery to ensure it was a reg/rec issue and bike still ran, everything worked except I wasn't getting a spark at the plugs, I figured high voltage had fried the cdi unit as I got a continuous ignition circuit but just no collapse causing the spark.
Replaced the regrec, new battery and cdi unit today
stuff gets worse!!!
The bike fired up first go no bother, regrec was charging on idle but when I revved to 5krpm (max charge) the voltage actually dropped a few 10ths instead of increasing, checked the ac current at the 3phase plug where it enters the regrec and it was approx 4.3V accross each of them and it dropped slightly at each when the bike revved.
Put the bike backtogether regardless to go for a test ride to ensure everything else worked and went out of garage to start it... No spark again so no start!
I am at a loss, I think I hav a wiring loom issue ( next thing I'm checking tomoro after work ) to the cdi unit and also is ther a problemwith my alternator? Anyone had any of these problems before or any advice on what to check? All help and tips and suggestions are very welcome!!

[fastdruid]

Curvy I presume?

Common issue is where the loom is pinched behind the seat bolts, if you're not careful you end up with the bolt out the back pressing into the loom where over time it chafes and then earths. This can result in all your symptoms.

Druid

[Biker Biggles]

4.3 Volts AC at the three yellow wires from alternator to reg/rec is wrong.That should be about 60 or 70 volts AC.

[TSM]

do an impedance check on the stator from the closest connector, this will tell you if they are proper stuffed

Does anyone have any more ideas about a reason for no spark? I need the engine fixed to fix/test the charging system anyhow, i need to focus on y the bike started then stopped again, I hav determined the original stop on motorway cud have been a powersurge from broken reg/rec that took out cdi unit as I hav a few blown bulbs on bike etc also, however I replaced cdi unit and it fired up a few times but soon as the plastics went back on we hav no spark! Checked continuity of power from battery to coil and coil to cdi socket and it was there so y else could I not be getting a spark now and I was yesterday? Anyone know how to test a cdi unit also??

[TSM]

Originally Posted by Ceebl

Does anyone have any more ideas about a reason for no spark? I need the engine fixed to fix/test the charging system anyhow, i need to focus on y the bike started then stopped again, I hav determined the original stop on motorway cud have been a powersurge from broken reg/rec that took out cdi unit as I hav a few blown bulbs on bike etc also, however I replaced cdi unit and it fired up a few times but soon as the plastics went back on we hav no spark! Checked continuity of power from battery to coil and coil to cdi socket and it was there so y else could I not be getting a spark now and I was yesterday? Anyone know how to test a cdi unit also??

check the pickup coil, without it the CDI does not know the engine position to fire the spark

[fastdruid]

Originally Posted by Ceebl

so y else could I not be getting a spark now and I was yesterday?

Sometimes I wonder if I'm talking to myself.

Druid

Originally Posted by fastdruid

Sometimes I wonder if I'm talking to myself.

Druid

I get that feeling a lot too.

Attitude Druid? Iv checked the loom tnyt and checked anything else I can think of with a multimeter, I wouldn't ask again if I hadn't already exhausted the options.
Basically if I earth the plug and short it myself to the battery I am getting a spark when I break the connection with a wire, there is continuity among the whole loom including across the coil and in the lead from the coil to the cdi unit. Basically I believe it is either another cdi unit has mysteriously blown or there is a problem has coincidentally occured in the timing system that controls the cdi unit.
Therefore my current problem is does anyone kno how to test a cdi unit?

Originally Posted by TSM

check the pickup coil, without it the CDI does not know the engine position to fire the spark

This is one of my potential theories, does anyone kno what the resistance across the pickup coil is meant to b and how do I get at it to check it?