Can anyone please give me any tips or advice on rebuilding,
The guy I got it off, didnt mix enough oil into fuel and its toast...
Any help would be great.

 

Act like it's any normal 2 stroke. Drain the water, pull off the head and cyl. Have it bored to a new sized piston. Order a gasket set. Once it's bored out, reinstall it. Break it in and enjoy. I left out a lot of steps so if you have never done one before, get a buddy that has and watch him. And remember: their is no stupid questions - just answers. Remember to use the right mix. I like Golden Spectro with Turbo Blue race fuel 50:1 mix.

Note: Also check your jetting and make sure it's not to lean.