Use a smear of grease to hold the gasket in place.... my motads fitted a treat
make sure you have completely cleaned the exhaust port where the copper gaskets sit, I held my new copper gaskets in will a little exhaust paste,a little bit of fiddling and the pipes lined up, the only issue I had was the where the exhaust went under the engine the centre stand fouled them when being raised and lowered, I ground a little bit (1-2 mm off the stand where it rubbed, job done
I did have her running, just slipped the link pipe on and my new exhaust without sealing them and it sound amazing but i couldn't feel any leaks. I read that new pipes can sounded abit tinny so I might be that and the smell of burning wd40.Is there an easy way to check for leaks without roasting the crap out of your hand!