Tyre Question

[mkg81]

This is my first posting. I have just acquired a 1978 900ss. Its been off the road for 4 years but is good useable condition

Unfortunately the seller when presumably preparing it for sale applied some silicion type cleaner to the walls of the tyres. I know this is not a good idea on motorcycle tyres!

The problem is that there is some overspray on to the edges/shoulders of the tread. A friend ( and a mechanic) suggests that this is potentially dangerous and that I should fit some new tyres-just in case. He suggests that the silicone "soaks" in and won't clean off. Will this overspray clean off once its on the road (taking it nice and easy obviously) or should I junk the current tyres and get new ones? It would be a shame as the tyres look hardly used.

Any advice/thoughts greatly appreciated.