According to haynes manual I should replace the chain when tip of middle block lines with red zone ok i understand that but...the sticker on my bike has no red zone How many mm back from the inner right hand side of that empty rectangle to the left of the red zone is it?

Check out this thread for details:

viewtopic.php?f=23&t=22841

That is assuming that you're running standard rear sprocket size.

Thanks but the stickers not only different on an RVF, or at least mine, they dont say where the red line is 'in relation to the bike itself...but a search on google and i heard of a 'black line' so i'll have another look at it tomorrow

can you pull the chain off the sprocket at all?

What makes you think it may be worn?

the sticker is just a guide..and a shit one at that,

chain slack should be 15-25mm not 'pull offable' before you replace it I can no longer tighten the chain to stay in the proper slack...so i'm going to get D.I.D. 15T front sprocket and D.I.D. x-ring 525 102link chain but I'll need to find a 38T sprocket somewhere, places only want to sell me 40T...forgive me for not wanting to change the acceleration and leave it stock on 38T...