Hi all I've just got a cheap Polaris Hawkeye to fix up.
It does run fine under the following conditions, you need to hook it up to a 70amp hour 12v that normally starts a 4x4. The battery that came with it a 10amp won't even make the relay tick. So I bridged the relay and the starter motor turns the engine over for about two seconds then sounds like it's free spinning as if it can't spin fast enough to engage the starter clutch. So I tried the battery off my girlfriend's car a 40amp and now the starter motor turns off the key but free shipping.
So not to be beaten I went all out with the big badboy one and if fired up straight off the key every time

 

Push comes to shove I'll strap the big battery to the front of the quad. Job done

 

Get the correct battery for the Hawkeye.. If it still has problems in cranking then either the starter or starter clutch could be the problem more than likely. Even a bad solenoid or corroded connections could be causing the problem. Shouldn't take a car battery to crank one up.. You can look up parts here for your model and find replacements on ebay.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse Plus voltage isn't the problem in using a larger battery,the amperage is. If to many amps are used,problems can happen as the manuals say.
"Amperes (amps) are the units used to measure
current flow in a circuit or through a component.
Current is the actual flow of electricity. The more
current that flows , the more work that can be accomplished.
However, if excessive current flows
through a wire, the wire will overheat and probably
melt. Melted wires are caused by excessive current,
not excessive voltage."