I spent some time waterproofing the bike- vent hoses up etc etc. For a while it was a proper submarine but steadily became more and more sensitive to water (stalled).
Liberal applications of wd have been the norm after a ride to drive the water away.
A week or so ago I tried to pull the plug cap off- stuck firm-. Tank off and a bit off huffing and puffing it came out but with ony the outside half of the rubber seal that fits arround the spark plug. I dug the other half out and off for a new plug cap.
Comparing the old and new rubber seals- the wd had swolen the old rubber to twice its normal size- it was a baggy seal arround the plug and let water in.
New plug cap -sorted. trip out in the wet today no probs.
By the way I was quoted £20 odd plus VAT for a KTM cap, about £17 for a BETA plug cap. Got same one from Pete at Westcountry motorcycles (by Plessey)for £2.70 plus VAT. Top man