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Easy way to bypass EXUP valve?
Posted: Sat Oct 08, 2016 3:25 pm
by johnfellows
Hello, I've tuned my carbs and my bike is running better, but still having weird issues when hot and low rpm. In an attempt to diagnose I want to disable the exup valve and see how it runs. Could I just unplug the servo motor? Does the valve stay in the open or closed position when off? Would this cause any damage to anything? Thanks
Re: Easy way to bypass EXUP valve?
Posted: Sat Oct 08, 2016 6:53 pm
by DonTZ125
Depending on which year your bike is, unplugging the EXUP may cause the TCI to limit the revs to 4k rpm.
Assuming you were idling the engine when you switched off the key or kill switch, the EXUP will be in the closed position. You can disconnect the cables, and pin / wire the valve pulley in either the open or closed position.
Re: Easy way to bypass EXUP valve?
Posted: Mon Oct 10, 2016 5:10 pm
by johnfellows
Thanks for the tips. I decided to just get in there a bit more today and look things over. Here's a video of mine. Does it appear to be operating properly? The top cable seems a bit loose, but is it still moving enough to open fully? MY bike is having issues at low rpm and runs fine at high rpm. So I'm assuming this isn't the issue since it's staying closed at low rpm as it should.
https://www.youtube.com/watch?v=JBPExQLzwpc
Re: Easy way to bypass EXUP valve?
Posted: Mon Oct 10, 2016 7:03 pm
by DonTZ125
Your cables are badly out of adjustment. The fork on the pulley should align with the hole in the housing at idle.
Re: Easy way to bypass EXUP valve?
Posted: Mon Oct 10, 2016 7:39 pm
by johnfellows
Oh no! Where do I adjust the cable free play?
Edit: Just kidding I found where I can reach them.