ive been told that the stock battery is too small for the bike. guy at the bike store told me that i could go up to a 14 as apposed to the 12 in the bike? can i? has anyone done this before? again, help! i just had the start clutch replaced and they said the small battery helps to cause this problem. i don't mind modifying the battery case. most of the 14's i looked at will fit except they are too tall. that i can fix. need help if anyones does this. thankyou, mike
Do you mean replacing 12 Volt battery with 14 Volt one? I don't think you can do that. Your entire electrical system will get screwed up. The only thing you could do is to replace with the battery of higher capacity/max current, but it still should be 12V.

Myabe your battery is bad, and you need a new one. The reasoning you are giving in the post doesn't make a lot of sense. What does it mean a stock battery is too small for the bike? Sounds like BS unless you clarify.

I would say no you do not need a larger battery.
A 14 is what would go in a older bike or 4 wheeler.
A bad, old or ill tended battery is more likely the problem.
It wouldn't affect your clutch any.
The startor maybe.
YTZ14S Yuasa fits the stock battery box and has higher capacity (235 cranking amps) to help minimize starter clutch kick-back. It also helps to keep the starter button ENGAGED until you are SURE the engine has fired up.
There are a couple people who are now saling a battery for the busa that is supposed to be better than stock. I'll see if i can find the magazine article and post it. 14 should work somewhat better than the 12, but the key is battery maintainence
speaking of bigger batteries and such... Anyone do any alternator upgrades? One of the members here gave me some good ideas on the stereo system install for the Busa... I am going to install one similar here in the winter...

as you can see the 14 i am talking about is the # prefix.busa 12... the clutch is the starter clutch.thanks