I have tried numerous things in the past, checking and adjusting the routing of the plug leads, changing the leads when they show signs of rubbing, using Magnecor leads, applying damp start, waxoil to the inside of the rubber boots. All having little effect over time. So bad that this week the bike was already misfiring and cutting out when new leads were only fitted 3 weeks ago. Checked the front lead and was already showing signs of rubbing.
My fix.Take 2 lengths of 12.7mm/1/2 inch heater hose, about 2 inches shorter than the length of the spark lead without the rubber boots fitted.
Thread the leads through the heater hose and then refit the rubber boots using some silicon sealant.
Refit the leads to the sparkplugs and coil.
Now the plug leads cannot rub directly against the throttle cables, engine, mountings or frame.
Went for a 50 mile ride straight after to test. Anyone in the midlands/north of England who has stepped outside today will know how bad the rain is/was.
For the first 30 mins I rode with the same expectations as normal, waiting for a change in engine note, a splutter, a misfire and the dreaded cutting out.
On the motorway the truck wash occasionally caused a cough but nothing more. On the B roads round Squires, the roads were totally awash, deep puddles, deep enough to push my feet of the foot pegs but nothing went wrong. The bike kept running, off the throttle it returned to a smooth idle, at the lights/junctions it would sit there happily ticking over.
Finished the ride with a huge smile. Just able to concentrate on the riding, being smooth and setting up for corners and other hazards correctly and generally actually having fun.
Touch wood, this mod is working.
Just need some new waterproof boots and gloves.
......
in the uk 
