The YTZ14S has higher Amp-hours than the 7S. Long term, I cannot see any issues, maybe longer term motorcycle veterans here can come up with something. The bike is running on the alternator most of the time (unless you have a diesel
), so I think the spag clutch is the biggest concern. Lots of people have their spag clutch break with 14Ah batteries, so who knows. I think it is UncleErnie who says "you pay your money and take your chances."
Really I think the only issue is do you use your ES a lot, do you hold the starter button for a while? Once the bike is running the alternator should be doing the work. I don't do either. One other issue is being careful that the positive post doesn't touch anything while the negative is connected. That will make a spark, probably blow a fuse, possibly fry something. Really you have that same concern with a 14Ah battery too.
I like it, I think it looks good.
Just my $0.02 and probably more than it is worth.
Good luck,
-Rick