Gs450l abrupt loss of power?

[pete]

Interesting, pretty sure the LT side should be 3 - 5 ohms, but they both sound consistent.

HT on the right looks a bit low, pretty sure it should be more like the left one, so plug cap might help there, at least they're cheap!

To test for 12v at the coil, simply turn ignition and kill switch on and measure between ground and the orange/white wire on the coils.

[83Rabbit]

hhhmmm ok well Ill check the voltage to the coils and then go from there, Ill also pull down the right carb and re-soak everything and go through it again for sh**s and giggles....

the actual ignition unit itself wouldnt be going bad would it? Where do these bikes get their signal to fire? stator/flywheel?
Thanks

[pete]

It's certainly possible, but that typically is no spark, not weak spark.

You'll find the signal generator under the timing cover on the right side and the ignition module itself on the electrics tray under your left side cover...

[83Rabbit]

OK, Im STUMPED!

Got a Voltmeter, left side is about 10.5V, right side, the BEST I could get was 6.3, but mostly it measured mV it was so low. Power is so low it wont even light a test light, left side will easily light one....
But heres whats odd... when pulling the plug and cranking the starter, the plug sparks with no issues.... How could I have less than 1v with the key in the on position at the coil but the plug actually fire when its cranking???

Where do I go from here? Pull and replace all wiring related to the ignition? The only spade connectors I see for the system are the ones at the coil. Anything I can test next?

[BassCliff]

Greetings and Salutations!!

Hi Mr. 83Rabbit,

It sounds like you may have a lot of corrosion throughout your wiring harness. Check and clean all electrical connections and grounds from the headlight bucket to the tail light. See the troubleshooting tips on the electrical page of my little website. You might want to consider the coil relay mod.

Anyway, let me dump a TON of information on you and share some GS lovin'.

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Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

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Thank you for your indulgence,

BassCliff

[pete]

OK, Im STUMPED!

Got a Voltmeter, left side is about 10.5V, right side, the BEST I could get was 6.3, but mostly it measured mV it was so low. Power is so low it wont even light a test light, left side will easily light one....
But heres whats odd... when pulling the plug and cranking the starter, the plug sparks with no issues.... How could I have less than 1v with the key in the on position at the coil but the plug actually fire when its cranking???

Where do I go from here? Pull and replace all wiring related to the ignition? The only spade connectors I see for the system are the ones at the coil. Anything I can test next?

Ok, either you're measuring in a weird way that's giving those poor results or you have a serious connection issue, which means BassCliff has got the right stuff (as usual )

So, how are you measuring? I need to know exactly where you're putting the positive and negative probes of the multimeter.

If your measuring technique is ok, then it has to be connections and/or grounds.

When I put my harness back on, I gave every single connector a good squirt with contact cleaner and connected and disconnected what it plugged into a few times to give them a good scrape clean. I also visually inspected them to double check everything looked good.

After doing that throughout the entire harness, I still was dropping 1.5 - 2 volts to the coils, so I ended up dismantling and cleaning the ignition switch and the kill switch, and that got rid of the voltage drop so I get 12 volts or more at the coils and have maybe 0.5 volts drop from battery to coils which I'm pretty happy with.

You also need to make sure every harness ground connection is healthy, and preferably move as many grounds as you can to a single ground point that also has a connection directly back to battery negative. This will also help your charging circuit as it needs a good ground to operate effectively.

Welcome to the world of 30 year old Suzuki wiring harness fun

[83Rabbit]

Im measuring positive probe to positive coil input terminal and negative probe to negative input terminal with the leads connected to the coil, also tried the same with the leads disconnected measuring the leads themselves.

I see in the diagram that there is one orange and white wire coming from the ignitor and that somewhere it splits to two o/w, one for each coil... Wheres that split?
Whats to clean in the start and kill switch? Those connections are soldered, right?
Thanks for your help again guys.

Odd how this just all of the sudden happened, bike was running well enough for half the trip

[pete]

Im measuring positive probe to positive coil input terminal and negative probe to negative input terminal with the leads connected to the coil, also tried the same with the leads disconnected measuring the leads themselves.

I see in the diagram that there is one orange and white wire coming from the ignitor and that somewhere it splits to two o/w, one for each coil... Wheres that split?
Whats to clean in the start and kill switch? Those connections are soldered, right?
Thanks for your help again guys.

Odd how this just all of the sudden happened, bike was running well enough for half the trip

Ok, when we're talking about measuring voltage at the coils, it's actually from the orange/white to ground somewhere. We want to see what voltage is going to be used to charge the coils up.

Inside the ignition and kill switch there are contacts that meet when rotate it or flip it on/off, and those get covered in crud over time. The contacts in there were quite dirty on mine.

Ignition switch Before:



After:



Kill switch:



I think you'll get the idea...

[83Rabbit]

Ah, so positive input on coil, to any ground, coil mount?
Not actually the negative terminal,on the coil itself?
Thanks

[pete]

Yep, that's it, pretty much any bare metal will do, but preferably an actual ground point for the harness or the negative battery terminal.

[83Rabbit]

Yep, that's it, pretty much any bare metal will do, but preferably an actual ground point for the harness or the negative battery terminal.

Will do that tonight and take new readings, still odd that one side read so different than the othet.
I did clean up the negative battery lead/ground to the motor last night, that was all rusty, now its shiney

[pete]

Will do that tonight and take new readings, still odd that one side read so different than the othet.
I did clean up the negative battery lead/ground to the motor last night, that was all rusty, now its shiney

Good stuff.

If you want to know the difference it makes, measure properly before and after, you may be surprised at the results, I know I was! Went from something like 10 - 10.5v at the coils to over 12v...

Oh, and if you haven't replaced the glass main fuse in a while, do it anyway as they've been know to measure good but fall apart when being checked... I replaced mine with an inline blade type.

[83Rabbit]

Ok, using the new method I got 11.5v for each coil...wth... I guess ill start tearing into the carbs again???

[pete]

11.5 should be workable if not ideal.

Before going back to the carbs, I'd still make sure your sparks are good.

Just eliminate one thing at a time so at the very least you know where the problem isn't...

BassCliff's site has a PDF there on replacing the spark plug caps.

If you don't want to buy new plug caps without knowing if they'll fix the problem or not, you can at least do part of the work by taking the existing ones off, stripping some of the HT lead back, cleaning up the end of the plug cap and putting it back on again.

If one of the plug caps is dodgy, you will probably find it comes off very easily and when you put them back on, you should see a very different resistance figure to what you had in post #15.

[83Rabbit]

The caps on there now simply thread into the center of the wire. Ill trim some wire and swap caps, see if that changes any values.
Thanks!