Persistent exhaust leak, BMS Heritage 150, GY6

[SpectreGadjit87]

Ok, so, I’ve gotten some invaluable advice off this site but it’s my first time asking the scooter universe for advice.

I recently replaced the head on my scooter, due to stripped out spark plug threads. In doing so I had to remove the exhaust pipe, which was rusty enough for the weld between pipe and muffler cracked about 70%. After trying about 6 different quick-fixes from the auto parts store, and then chipping and grinding them off, I re-welded it. Did the soapy water test and didn’t get any bubbles so I reinstalled it.

Now here’s where it gets interesting.

I got a stock replacement gasket and put it in, and there was an obvious leak. Long story short, the flange of the exhaust pipe is warped long-ways from bolt hole to bolt hole. I’ll go ahead and say I’m planning on getting a new exhaust, however my question is this: If the timing is off by, say, a single tooth, could that mimic an exhaust leak? ie: a slight, short bogg at wide-open throttle? I ask because before changing the head I forgot to set it at TDC and had to fiddle with it a bit to get it running (I assume) correctly. Look forward to your wisdom, thanks!!