robin 35

GoldenMotor.com

webhead

New Member
Jul 27, 2011
2
0
0
bend oregon
first off I'll say hi, I've been lurking, reading, searching etc... I've got a robin 35cc, I've seen posts before on additional power from a small 4 strokes, and am wondering.... a 1/2" exhaust pipe with a small silencer could really open up the exhaust side of the equation.... is there a reason that we haven't seen a cool (read performance orientated) exhaust? I know that our gains are minimal, but.... not only would there be some power increase, if from nothing else than straightening the exhaust out, much less loosing a ton of restriction/ weight/ and if done correctly it could look really cool. (I know, back pressure is a good thing as well)
 

wheelbender6

Well-Known Member
Sep 4, 2008
4,059
221
63
TX
Four stroke motors don't benefit from exhaust tuning as much as 2 strokes. Bigger valves and higher lift cams really spice up a four stroke, but that is expensive.
 

webhead

New Member
Jul 27, 2011
2
0
0
bend oregon
Four stroke motors don't benefit from exhaust tuning as much as 2 strokes.

while I appreciate the input, I stated that while our gains are minimal...
 

happyvalley

New Member
Jul 24, 2008
784
1
0
upper Pioneer Valley
Quenton from EZM claims to have worked out some performance gains with his flex exhaust though it's on the 49cc HS engines. He has stated length and pipe ID are critical as tested on a dyno.