Two Stroke Idle Sound

[launboy]

This doesn't just apply to two PWC, but I've noticed that pretty much every two stroke makes a bum bum bum almost popping sound at idle. I don't know how to write it, but you can hear it in this video. Kind of always wondered why?

[video=youtube;LAbv0cmCPvE]http://www.youtube.com/watch?v=LAbv0cmCPvE&feature=related[/video]

Adam

 

[Sink]

I believe it is caused by the overlap of the intake and exhaust. Burning fuel before the port closes... As opposed to an extra stroke in between. Just makes sense to me. Any other ideas out there? I've also heard it is the reed valve but do all 2 strokes don't use a reed valve, right?

 

[launboy]

I thought it probably had something to do with the exhaust, just not sure what exactly. What you said makes sense though. I don't think it's the reed valves because my 657 and 787 both have rotary valves and make the sound too.

Adam

 

[Seadoobuddy]

One other thing I notice in the beginning of the vid. is that I saw NO water coming from the tell tale in the back, unless it was moved to a side.
Granted It was shown only at the beginning so maybe it started after the pipe filled with water.

Sound pretty normal to me.

 

[LouDoo]

My 96GTI sorta lopes, kinda like an old Harley, I'm not sure why, maybe the pipe is a little longer. I love the sound it makes.

Lou

 

[Sink]

must be the big cam! lol