No spark from plugs
Discussion
I'd observed that my 1999 SV650 doesn't like the rain very much when a couple of times after a heavy downpour it would idle poorly for the first minute after starting. This time though, after leaving it unused and exposed to the elements for a month, it would't even start. I tried bump starting it by rolling it down the long, steep hill by my house, only to arrive stationary at the bottom. In the pouring rain. On a Monday morning. Pushing it back up it very nearly finished me.
A further 2 weeks followed before I forgave it enough to even be able to look at it, so with my limited mechanical knowledge, began troubleshooting. I pulled the plugs and noticed there was no spark from either of them, so replaced them with new plugs only to find, somewhat predictably, there was still no spark. Recognising that my bike knowledge had been exhausted, here I am to re-stock.
So, what possible reasons are there that there would be no spark from the plugs?
A further 2 weeks followed before I forgave it enough to even be able to look at it, so with my limited mechanical knowledge, began troubleshooting. I pulled the plugs and noticed there was no spark from either of them, so replaced them with new plugs only to find, somewhat predictably, there was still no spark. Recognising that my bike knowledge had been exhausted, here I am to re-stock.
So, what possible reasons are there that there would be no spark from the plugs?
Remove any bodywork and locate the wiring harness connectors; disconnect them and check the pins/sockets for corrosion or water ingress - Suzuki harnesses rarely have sealed connections and once water has made its way in or you use the bike year round a quick check/clean and grease will usually have you back up and running
Limited knowledge, not no knowledge. 
Limited to knowing that when the starter motor is pressed (assuming sufficient battery voltage, ignition on, kill switch not engaged, etc) that with the spark plug removed and the HT lead attached, a spark should be visible. Yet, it quite clearly isn't sparking, and that's where my knowledge ends.
The bike is left out in all weathers with electrical connectors hanging loose all over the place, so an electrical short due to water ingress is a strong possibility. I was just expecting it to be more resilient to a life outdoors.
Front drainage hole was my starting point, although I thought this would be more likely to cause a failure of 1 plug, not both. Neverthless, the channel was clear, and there was very little corrosion around the plug on removing it. I'd hoped it would be that simple too, but sadly not.
Limited to knowing that when the starter motor is pressed (assuming sufficient battery voltage, ignition on, kill switch not engaged, etc) that with the spark plug removed and the HT lead attached, a spark should be visible. Yet, it quite clearly isn't sparking, and that's where my knowledge ends.
The bike is left out in all weathers with electrical connectors hanging loose all over the place, so an electrical short due to water ingress is a strong possibility. I was just expecting it to be more resilient to a life outdoors.
Front drainage hole was my starting point, although I thought this would be more likely to cause a failure of 1 plug, not both. Neverthless, the channel was clear, and there was very little corrosion around the plug on removing it. I'd hoped it would be that simple too, but sadly not.
Edited by CrankyCraig on Sunday 20th January 02:02
I'll assume you missed out the "and the spark plug body grounded to the bike" on purpose. 😀
I'm going on old bikes here, but you could connect the terminals of the coil directly to a battery and tap the positive on and off the battery terminal. If you get a spark, you know there's nothing wrong with that end of it. Or maybe that doesn't work on anything built after 1975.
I'm going on old bikes here, but you could connect the terminals of the coil directly to a battery and tap the positive on and off the battery terminal. If you get a spark, you know there's nothing wrong with that end of it. Or maybe that doesn't work on anything built after 1975.
Yes, the plug was grounded. I tried it in a couple of locations just in case, and nothing. Wasn't brave enough to test it on my tongue though, but I'll stick a meter on it and see what I get.
Seems really daft now, but after 2 months of not using it I can't remember whether the clutch has to be pulled in to start the bike. I always do, and strapped it in to test it, but I can't remember whether it's necessary. The side stand cuts the engine if it's deployed and put into gear.
I've drained (but not yet replaced) the fuel, and some of the crap that I found in the tank could definitely help to explain the rough running, but I'm trying not to think about the carbs at the moment.
Fortunately, it's now drying in a heated garage, so the new plan is to check it periodically while working my way through the electrical components and weather proofing them. Not sure what other options I have.
Seems really daft now, but after 2 months of not using it I can't remember whether the clutch has to be pulled in to start the bike. I always do, and strapped it in to test it, but I can't remember whether it's necessary. The side stand cuts the engine if it's deployed and put into gear.
I've drained (but not yet replaced) the fuel, and some of the crap that I found in the tank could definitely help to explain the rough running, but I'm trying not to think about the carbs at the moment.
Fortunately, it's now drying in a heated garage, so the new plan is to check it periodically while working my way through the electrical components and weather proofing them. Not sure what other options I have.
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