Am not keen on having to remove the mufflers for the job - did you do the holesaw work with the mufflers in-place ?
Thanks for the advice !
The hole will be larger than the plug after drilling.By starting the bike you should be able to blow the plug out by reving the throttle .As the holesaw begins to finish the cut, you can feel the pressure starting to relieve...kind've like it's becoming butter. When that happens, take pressure off of the drill and ease it through. If the center drill is sharp, and if you get lucky, the plug you drill out will be attached to the center drill bit when you pull it out.
The hole will be larger than the plug after drilling.By starting the bike you should be able to blow the plug out by reving the throttle .
Watch a guy on Youtube and when he started the bike that had a similar freeze plug it blew out on start up,lol.Maybe if everything lines up just right but the odds aren't great. But for sure that will happen with all the metal particles - I certainly wouldn't worry about those.
Could you have gone bigger with the drill bit? Say 1.5"?I followed member Moleculo's advice with a 1-1/4 in holesaw (see pic, with a pilot centre bit fitted to it), you'll also need an extender rod as the baffle plug is about 6in inside or as I did rigged up enough adapters for the reach. Rattles a bit until it centres then a bit of smooth pressure & 30 sec - 1 min and your through.
If you're going ahead, be prepared for a bit of fiddling to retrieve the drilled out plug & swarf !
Good luck !View attachment 6093