No spark. 6 hours doing multi-tests. What to do now?

My SV hasn't started for two months, having previously worked faultlessly fo two years. I've added to a few relevant threads and taken some advice from you guys, but still no joy. Essentially everything works, turns over, but no spark at either plug. I have sourced a second hand stator/signal generator, but took YC'S correct advice that I should do some more tests before buying it.

Here's what I found today!

Battery output: 12.57 volts. As intended.

Power to coils: F 20-25v. R 22. Is this right, seems on the high side?

Coil resistance across coil terminals: F 4.4 Ohms. R 4.4 Ohms. As intended.

Coil resistance across + terminal and HT lead: 24400 Ohms on each. As intended.

Spark plugs look fine, and were replaced 4k miles ago.

Power to ICU: 11.81 volts. Bit low maybe?

Power to ICU with kill switch off: Meter fluctuates all over the place. Possible fault here?

Signal generator peak voltage reading: 1.05 volts at ICU and connector. Should be 3 volts. Possible fault here?

Signal generator resistance: 64.9 Ohms. Should be 140-230 Ohms. Possible fault here?

Stator coil test: Continuity between all three ouputs, none between either output and earth. As intended.

Earths. Starter motor and Oil pressure switch look good. Cleaned and retightened. Can't access main one. I've just been reading a thread about introducing a temporary one so will do this and retry.

All fuses fine.

Ignition. Shows continuity when and where it should. Resistance of 100.1 Ohms on anti-hotwire lead. Should this be 105?

Neutral switch works.

Clutch switch works at lever, but could test further up wiring loom if people think I should?

Sidestand switch didn't show continuity when up, which made me think I'd found the fault! Removed and bypassed for now. No spark! . I think I'm right in thinking I can just twist the two wires together?

Any advice would be superb, shall I go ahead and purchase the stator/signal generator?

Beers for helpful people at this years AR if A, I go. B, they go. C, it works!

12.57 from battery seems low to me normally 13ish but I have had a spark from a battery at 11.5v

On sidestand yes you can twist the wires together.

Is this a curvy or pointy?

It's a curvy!

Originally Posted by sam hagger

Battery output: 12.57 volts. As intended.
Power to coils: F 20-25v. R 22. Is this right, seems on the high side?
Power to ICU with kill switch off: Meter fluctuates all over the place. Possible fault here?
Signal generator peak voltage reading: 1.05 volts at ICU and connector. Should be 3 volts. Possible fault here?
Clutch switch works at lever, but could test further up wiring loom if people think I should?
Sidestand switch didn't show continuity when up, which made me think I'd found the fault! Removed and bypassed for now. No spark! . I think I'm right in thinking I can just twist the two wires together?

12.5 is good.
How can you measure 20V at coil when you only have 12.5 on battery??
Clutch and sidestand switches work since your motor is turning over, nothing wrong there.
To get spark you need power from kill switch through orange/white wire. This wire feeds coils and ICU with power. If you have 12V on that wire coming out of kill switch than you only need 2 more things. Signal generator and ICU. You can borrow ICU and try, if still nothing open engine cover and check signal generator. This after you make sure you getting 12V out of kill switch.

12.5 is well low, should be 12.8 ish fully charged.

As above if it was me i would want to test a spare icu on it next. If it does turn out to have gone, you might want to then look at your rectifier to see the what the charging voltage is.

Originally Posted by beabert

12.5 is well low, should be 12.8 ish fully charged.

12.6 is normal to see from fully charged battery. Besides battery is not his problem, bike turns over. It will also spark even under 11V.

I agree its not the problem, just pointing it out, fully chareged is 12.7+

[Spanner Man]

Good morning all.


On the alternator stator you should have continuity between the three output wires. However, as this is part of the charging circuit, I doubt that it would cause a loss of spark.

Have you also checked for continuity on the signal wires from the ECU to the coils? It's unlikely that both would break at the same time, but you never know.

Check your voltage readings at the coils again. As, 20 odd volts is unlikely. For, as said, you only have 12 ish in the battery.

The signal generator resistance is very low, this may indeed be the culprit. Unfortunately the only way to test this is to replace it.

One possibility is that the bike had an alarm fitted which has since been removed. Some years ago I spent a while on a non sparking RF900. It turned out that some moron had removed an alarm & just twisted the relevant wires together, before taping the loom up. They were making contact, so continuity was fine, but when asked to carry current they didn't play ball.


Cheers.

Originally Posted by Spanner Man

Good morning all.


On the alternator stator you should have continuity between the three output wires. However, as this is part of the charging circuit, I doubt that it would cause a loss of spark.

It will not, stator has nothing to do with spark. You can take it out or unplug and bike will run, until battery goes somewhere under 11V.

Voltage at coils on mine is 13V at one side and alternating 11 - 13V on other