99 X model has no spark after battery explosion

Evening all,

My mates SV (1999, think it's an X model) is causing havoc and pain. Story starts when the battery died, so she fitted a Lithium Ion box of witchcraft. Charging was checked in case the reg/rect had ********ed the old battery, it was reading 14.5v at 5K revs.

6 miles up the road, the battery exploded.

We now have a bike that will light up when the key is turned, and will spin the engine over, but has no spark on either cylinder. Also of note is that all the bulbs that were on at the time-head, tail, pilot and left indicator-are blown. I believe that when the battery went up, it took out anything that was turned on. All the fuses are OK, checked by multimeter not just visually.

I've gone through all the tests with a multimeter that the haynes book lists, everything checks out fine. This includes checking the 100 ohm resistor in the ignition switch. This, presumably, leaves the ECU/CDI/black box thingy as the main culprit.

She's bought another of these, but the bike is still dead. Could be that the second hand ECU is also faulty, or maybe there's something else that is also blown. Can anyone suggest what it might be?

What would be really, really handy is if someone near Derby, UK, had one of these bikes and would let us plug the new ECU into theirs and see if it works.

I posted this on the US forum, was told that the reg/rects can fail intermittently-hence she got correct reading when battery first fitted but could still have been faulty. I was told there's a better reg/rect unit available, can anyone advise?

[Sid Squid]

Do a regulator resistance test - I bet it's goosed.
It's likely why the original battery gave up the ghost, now a nice big fat voltage has been poked up anything in circuit when it went wrong, which sadly may well include the ignition unit.

Not heard of the resistance test, as I said it was measured as being OK when new battery was fitted but since been told they can have an intermittent fault. Going by your signature, is it a CBR part that is better? Which model?

I'm more used to bikes with kickstarts and points ignition, though the way this blasted machine is going it might end up running points! Works for my BMW...

[Bibio]

14.6v @ 5k is what you are looking for. dont bother with those lithion bats just get a good old lead acid.

might have taken the coils out rather than the CDI.

Yep, thats what she got for voltage. I checked the coils as per haynes book, resistances were fine. Just trying to work out what reg/rect unit is best to fit and available on fleabay. Found a few guides, looks easy enough.

[Bibio]

why are you looking for a reg/rec when the voltages are fine?

unhook the reg/rec then check the AC voltages from the generator which should be 70+vAC @ 5k (cold engine) on each of the three wires.

if that works out ok then plug the reg/rec back in and then check the voltage at the battery which should be 13.5-15vDC @ 5k.

if both the above works out ok then your charging system is fine. you can do a diode check if you like but you wont see the proper charging voltages if any of them are fubar.

Was told on the US forum that they can have intermittent faults, which might explain why half the electrics blew. Since they're a known problem it seems better to replace it anyway, rather than risk popping another CDI. We'll double check the figures when we do get it running anyway.

[Geodude]

I know a few who 99 owners who are still on the original reg/rec, dont know if you have already but have a check through the guides in my sig for a bit of info. hth