Re: Thor bore & stroke? Home › Forum › Ask A Member › Thor bore & stroke? › Re: Thor bore & stroke? BuccaneerUS Member - 1 Year (includes $3 online payment fee)Replies: 7495Topics: 1072 April 7, 2018 at 12:18 pm #73556 All I can tell you is that the bore is 2.000" on the 1937 2.4 hp. Prepare to be boarded!