Backfire and an Oil Leak. Any Ideas?

[AWTurboSP]

I have an '87 VT1100. I have two minor mechanical issues. The first is a leak from the oil filter. I have tried another new filter so it's not the gasket. Anyway to make this seal better? The other issue is a backfire on startup once in a while. And of course it's always when I'm somewhere I really don't want it to happen. It happens after it's been ridden then parked for a couple of hours. Not when it's totally cold or at normal operating temp usually. I appreciate any advice.

[fegs]

are u using the original filter? should not leak at all... backfire=lean mixture or predetonation due to cylinder temperature. you should be able to adjust mixture a 1/4 turn anc check.