I have one of these (even smaller) that I use. Can’t find a picture at the moment. Mine won’t cut a 7/8" pipe. Even leaves the copper tube rolled in on the end. Perfect for going into the water pump housing. Might save you a lot of time since it is a fresh water motor.

Available at Autozone for $8.99, but you can get all types from Amazon to eBay.

Dan in TN