From:Mutt Electronic:pigstye13 -A-
Subject:RE: RE: 165 vs 175 Date:Fri Mar 18 19:56:13 2011
Response to:15491
The only difference in the 165 (10 cubic inches) vs. 175 (10.7 cubic inches) is the added 1/8" stroke to the crankshaft. That gives it 10cc's more. If I remember right, the books says the 125 puts out 3 h.p., 165 puts out 5 hp and the 175 puts out 5.5 h.p. From what I've measured on most stock cylinders, the port timing is basically the same on all models. Exhaust port opens at 108- 111 ATDC and closes around 77 ABDC. Exhaust open duration is about 146. Blowdown is 12- 14. Transfers open at 121-125 ATDC and close at 61-63 ABDC. Transfer port opening duration is 116-118


Great question , I'd like to know myself, how bout it anyone have any thought's on this. Come on Mutt weigh in.

HI. Can anyone tell me how the 175 makes 5 more hp then the 165? That little bit extra stroke can't make 5 more hp. Thanks