6B-S
Bore is 2.5/16"
Stroke is 1.1/2"
and gives 1.25HP at 2200 R.P.M
can't find manual on the 8B-FB but have a 8B-FB and that was....
Bore 2.3/8"
Stroke 1.3/4"
and gives 1.73HP at 2200 R.P.M
Thks Its 1.5 stroke 2. 5/16 bore...
It looks very good with you, well done, the manual that I have list parts up to 901166, many will tell you that they didn't make them after the late 50's.