SMR 510 Engine Seize?

I just picked up a 2008 SMR 510 with 1500 miles on it, and have only ridden it 3 times (less than 100 miles). Yesterday I was cruising around some nice back roads, and on a straight away going about 75 my back tire locked up. Pretty frightening experience. I am new to huskys and have no clue what could cause this on such a new bike with moderately low miles. The previous owner told me he took it to the track a few times 'recreationally'. Has anyone experienced this? I know i will need a bottom end rebuild. has anyone installed a big bore 530 kit? what options do i have at this point?

Here are a few pictures:

If you are considering the 530 kit I would order ASAP from your dealer or one of the dealers on here as they seem to be getting pretty scarce . I 'm not sure Husqvarna is still producing them or exporting them or what the issue is , since these motors are no longer being used in the new bikes. As far as the engine seizing you won't know what caused the lockup of the motor until you tear it down and check it.