From:John Dutra Electronic:JMDUTRA -A- LIVE.COM
Subject:RE: RE: RE: 165 vs 175 Date:Sat Mar 19 12:25:34 2011
Response to:15495
Mutt,cubic inches... ? Other than that I totally agree with your analysis. Other than the fact that I dont understand half of what you said. Any good books you could recommend on the basic operation of a two stroke as I've really never understood exactly how they work. THATS RIGHT I ADMIT IT ! The first step to enlightenment is to admit ignorance grasshoppah.

----- ORIGINAL MESSAGE FOLLOWS -----
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

Mutt

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

----- ORIGINAL MESSAGE FOLLOWS -----
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