...every time I remove the valve cover?
EG when checking valves, replacing CCT.
The one I have on now was fitted a year ago and so far is undisturbed.
Unlike me!
Thanks all.

 

I'd say no but if you find it weeps a bit on the
front a little hi temp sealant would fix it it anyway
If it was 3 or 4 years old then I'd be thinking maybe
depending how hard and compressed it had become

 

I'm on the third one on my '90 CBR1000 that I bought new. I don't remember when I installed it, but it was awhile back. It was still pliable last fall and I reused it. I use Yamabond or one of the equivalents on the half-moons.

 

I've put one on in 7 or 8 years. Many valve checks, CCT work and no leaks yet. Use your old one, watch for leaks. If none, you're gold. If there's a leak, new gasket.

 

+1 for the very honorable !