Jetson car sound from 1st Gen

[oldfaithful]

I have had my 84 for just over a year now, and it's always had a slight sound that I've found annoying. I only noticed it at idle, but then I probably wouldn't notice it at an RPM or a speed much above that. I would guess it's what other members have been calling the Jetson car sound...sure seemed like that to me.

 

Well I've finally traced mine down to the YICS system. I guess that after exhausting other possibilities, it just became necessary to check. I tried spraying the system, but never noticed any change in sound or rpm. So I pulled off the YICS chamber(s) and plugged all of the ports/hoses on the engine...and the sound has gone away! I submerged the YICS chamber(s) and found a tiny, tiny leak at the seam on one of the chambers. It still seemed to hold vacuum pretty well, but under pressure there was 1 bubble escaping every couple of seconds.

 

Just thought I'd share what I'd found, since it seems a pretty common malady.

 

The Jetson car sound is gone...but now I can hear the clutch!

[DragonRider]

When I replaced my tranny in my 83, I completely removed the YICS system. When you do that you can either block off the ports or interconnect them, the left ones are connected together with a y connector so you can connect the vacum sensor hose to it, the right side just connect to each other, my bike seems to run much better than before and still getting great gas mileage. It was just one less thing to put back and have to take off later when it goes bad, and I didnt even check mine for leaks, it could have been leaking already.

 

 

I have had my 84 for just over a year now, and it's always had a slight sound that I've found annoying. I only noticed it at idle, but then I probably wouldn't notice it at an RPM or a speed much above that. I would guess it's what other members have been calling the Jetson car sound...sure seemed like that to me.

 

Well I've finally traced mine down to the YICS system. I guess that after exhausting other possibilities, it just became necessary to check. I tried spraying the system, but never noticed any change in sound or rpm. So I pulled off the YICS chamber(s) and plugged all of the ports/hoses on the engine...and the sound has gone away! I submerged the YICS chamber(s) and found a tiny, tiny leak at the seam on one of the chambers. It still seemed to hold vacuum pretty well, but under pressure there was 1 bubble escaping every couple of seconds.

 

Just thought I'd share what I'd found, since it seems a pretty common malady.

 

The Jetson car sound is gone...but now I can hear the clutch!