South West Bikers | Motorcycle Forum

Hey all,

I've got an odd issue on the Bandit in that when it's damp I get a misfire on plug 3. After a bit of riding when the damp stops it's fine. I've taken a look when it happens and I can plainly see sparks under the rubber boot AND above.

I order a new spark plug cap from wemoto, which turned out to be made of jelly and broke before fitting and instead snipped the lead in case it was damaged and re-used the original cap. This has made it better, but it still did it. Someone has mentioned that the coilpack could be gone but I just don't understand how that would make the sparks appear where they are.

Appreciate any insight

Thanks

I think it's on coils not stick coils. The seal is an oval shape, genuine would be the way to go, even dyna leads used to suffer in the wet.
Give it a bloody good clean and inspect for damage. Normally find ignition arking is due to oil and dirt holding moisture.

have you tried a new plug ,

The arc is caused by a release of energy to earth. It could be caused by a breakdown of the insulation or contamination as mentioned above. Thoroughly clean the plug and cap and look for obvious failure points. If you cant find anything and the clean doesnt cure it the replacement of cap and plug is a good option. If all the plugs and caps are the same age you may start to see similar failures on the other 3 caps or plugs. Hope this is useful for you

Yep - that's all great guys, cheers! Will give her a good scrub this weekend and see how it goes.

Once an insulator has failed it can be dead. The arc can burn the material and leave a carbon pathway that will be a weak point from then on.
As others have said, give it all a really good clean. Silicone spray can help too.