Misfiring / Power loss

I've got a 2000 SV650S which has sounded like it's been firing a tiny bit unevenly since I've had it.

Recently, I changed the spark plugs for the first time but I realised after swapping the old ones out that they were the alternate set of plugs recommended by the manual whereas I'd already bought the standard pair. I don't know if that's affected anything but since that time the bike has been misfiring and drastically losing power when riding (e.g. riding at "70" on the motorway and suddenly having virtually no power and being forced down to 50).

Eventually, through various gear changes, I've been able to get the power back to normal for a little while. There doesn't seem to be a pattern in what I've been doing with the bike - sometimes it's happened while accelerating, sometimes just going steady - except it seems to always do it when I'm first setting off (it's no fun crossing lanes of traffic and suddenly having no acceleration).

I've not got very much experience with bike maintenance so if anyone has any idea what the problem could be (and would be willing to explain it as though I've not got a clue) it would be very much appreciated.

Cheers,
Mark

[Sid Squid]

As the thing that set the problem off, (possibly), re-check that you have fitted the plug caps correctly first, and that also the caps are fitted correctly to the leads too.

Check those first and come back, it's always worth checking you haven't done something daft.

was it raining by any chance? or wet roads?

where you located

Yep, wet roads or rain every time I've been out on her since.

I'm located in the North West.

location being which town/city?
could it be missing on cyc. 1 because of the wet conditions? do you have a fenda extenda?

It will be the wet conditions. Mine runs like a dream all the time, until of course it is raining, or mildly moist on the roads. Eventually the moisture works its way into the spark plug hole and makes it run like a turd, sound like a lawn mower, and cut out whenever i pull in the clutch. Even have a fender extender on mine so short of some sealant round the lead, cant help!

northwind recommended silicone grease around the front plug-think maplan do it.

Originally Posted by arcdef

It will be the wet conditions. Mine runs like a dream all the time, until of course it is raining, or mildly moist on the roads. Eventually the moisture works its way into the spark plug hole and makes it run like a turd, sound like a lawn mower, and cut out whenever i pull in the clutch. Even have a fender extender on mine so short of some sealant round the lead, cant help!

my fenda extenda works a dream, in the snow, heavy rain everywhere. if your still having problems i recommend doing a insulation breakdown test on the front plug lead, the cap should have some form of rubber washer stopping most the mositure getting to the front plug, which is kinda useless without the fenda extender. but if the insulation is starting to break down then you get a problem as if the plug itself was getting wet.
pour water on the lead with engine running without the plug getting wet and see if the lead is breaking down.