bright spark

[coldtyres]

Hi guys.
I had a little trouble starting the bike tonight , bit lumpy so I had a look around and I could see a big blue spark coming from the lead to the front spark plug to the cylinder head. I turned it off and tryed to push the lead on tight and it seemed to be better so I got home and had a little look couldnt see a spark so I tried to push the lead tight onto the spark plug and got a bit of a shock.
Any ideas why she might be doing this?
It still runs so im not sure whether to worry, or, just stop touching the lead and keep riding the bike?
Whad ya reckon?
Cheers Ryan

Don't touch the HT lead! You might get a shock!
D'oh too late!!

Sorry matey, I'm not touching mine just to find out.

Electricity will always take the shortest/easiest route in a circuit. How old is the bike? Have the plug leads ever been replaced? If so were they good quality leads? Does the lead feel soft and floppy or hard and rigid?

Plug leads don't last forever. Over time the insulation breaks down and begins to get brittle. Tiny cracks can appear that let in moisture. Once this has happened, if the lead is close to something metal a spark will jump from the lead to the metal so avoiding the spark plug causing a misfire.

You can improve things by cleaning the leads several times a year with WD40. This expels the moisture and helps seal the cracks preventing moisture getting back in. This time of year on cold damp days this problem starts to show up.

If the leads are really bad you will need to replace them.

Kind regards
Tim

[Scoobs]

Originally Posted by I'm_a_Newbie

If the leads are really bad you will need to replace them.

.....which is quite expensive as they are attached to the coils.

Try the cleaning up thing first. To get to the front cap is a bit of a pain if you want to take it off. It's easy, but time consuming and awkward especially on an "S". Take the cap off clean and dry. Make sure there is no water in the plug hole. There is also a drain hole on the right side of the cylinder.