GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: adam89 on June 21, 2012, 12:27:48 PM

Title: vacuum ports
Post by: adam89 on June 21, 2012, 12:27:48 PM
ok so i think ive just about narrowed down my carb problem...it seems as though people on here have done away with there vacuum petcock...but what have they done with the vacuum port on the inside of the left carb? heres my problem: if i leave it unplugged then the bike idles fine and revs fine but i have to get the rpms to about 2500 before im able to shift or it bogs down and if im cruising then the bike bogs with full throttle but is ok with the rest of the throttle movement(1/4-3/4 throttle) if i cap off the vacuum then the bike will barely stay running and just shut off most of the time. how can i fix this???
Title: Re: vacuum ports
Post by: average on June 21, 2012, 02:16:51 PM
Go to your nearest autoparts store and grab a pack of vacuum caps for about 3-4 bucks. Kind of a pain to get it on there but it will solve your problem....
Title: Re: vacuum ports
Post by: bombsquad83 on June 21, 2012, 02:19:04 PM
That port has to be plugged if you are not using the vacuum tube for the petcock.  You probably need to adjust your idle screw after you cap it.
Title: Re: vacuum ports
Post by: tialloydragon on June 21, 2012, 02:58:34 PM
Isn't 2500 rpms a little on the low-side to be upshifting?
Title: Re: vacuum ports
Post by: adam89 on June 21, 2012, 03:19:59 PM
no, i was trying to explain that the bike runs better if the vacuum port ISNT capped/plugged off...if its plugged/capped then the bike would die...it the complete opposite of what it should be. thats what im not understanding???
Title: Re: vacuum ports
Post by: tialloydragon on June 21, 2012, 06:03:53 PM
Running rich maybe?
Title: Re: vacuum ports
Post by: twinrat on June 21, 2012, 11:44:31 PM
it is certainly an odd responce you are getting from caping your vac lines .Check that your diaphams are in good order ,i presume your carb jets are clear. check your compression, also  your valve clearances are set
correctly you can get some unusal things happening  if you have a problem with any of these 3 items,.