Is there space on either side the battery..? As long as it the same height and you have any additional space on either side of the that “7/8 you should be fine. As long as the battery also carries around same size CCA as the original and is an AGM which it states when I looked it up. What’s wrong with the original Yuasa battery that came in your ‘21 750..? Shouldn’t already be finished 4 years. I’m on my 6 year with my original Yuasa battery in my ‘19 750.

 

Hard to beat a Yuasa battery.

 

^^^^ --- All my motosport batteries are Yuasa's. Like AJ says .... size is important to fit. 1 inch longer is a lot for a cramped space. Also need to look at battery terminal placement. Left / Right and side vs top ... also type of terminal.

 

Great bit of extra info there on the battery. Didn’t think of those other things.