No spark from plugs

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CrankyCraig

Original Poster:

69 posts

73 months

Saturday 19th January 2019
quotequote all
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?




CrankyCraig

Original Poster:

69 posts

73 months

Sunday 20th January 2019
quotequote all
Limited knowledge, not no knowledge. laugh

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

CrankyCraig

Original Poster:

69 posts

73 months

Sunday 20th January 2019
quotequote all
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.


CrankyCraig

Original Poster:

69 posts

73 months

Sunday 20th January 2019
quotequote all
The stand was down when I tested it, but assuming it's functioning normally I wouldn't expect that to be the issue - the bike used to start with the stand down. That doesn't mean it wasn't acting up though.

I've got a meter, and a starting point. Thanks to all for the advice so far.