Hi guys, my one of my F1s has developed a sound that sounds like bubbles. It also doesn't seem to make nearly as much power as my other running one and that has 40k more miles and a misfire.

The power difference could be down to the high miler having a yoshi exhaust but even so this thing doesn't seem to have as much go as it used to.

What could cause the popping sound?
I'll try upload a clip to YouTube so I can share it

 

 

That certainly sounds like the exhaust is blowing from somewhere.

 

Yes I think you're right, thanks for the advice.
I tried tightening the exhaust header bolts and it got slightly better but I think the gasket is gone or something so I'll order a new one.