Watch "91 Kx80 walk around" on YouTube

[LEO DPRO 037]

You're probably sick of me flooding the site with my new KX80 but......
91 Kx80 walk around:

[video=youtube;IUS4x2H7Je0]https://www.youtube.com/watch?v=IUS4x2H7Je0&feature=youtu.be[/video]

 

[my67xr]

Nice, the idle is a bit high
But with 2 stroke MX bike's you normally have to keep your hand on the throttle to keep them idling

 

[LEO DPRO 037]

It drops off after a couple mins of riding. That was just after starting it first kick.
Is it true i should only be riding for around half hour at a time so it wont overheat? A few times it would spit coolant after returning from a long session, spoke to the bike mechanic i got the bike from and he said it would also get hotter due to being bored out having thinner bore walls.?

And will repacking the muffler give it more or less power at all?