1989 GL1500 Idle surge and carb question

[5150jim]

My engine RPM surges up and down while at idle. Engine runs rough and hesitates on takeoff. So my question is, do you thing carburettor cleaner or maybe Seafoam might help?
Or is this a vacuum leak?
Any idea how I can check for a vacuum leak?
TNX, Jim

 

[backyardtrouble]

Sometimes a vacuum leak can do that, or maybe a good sync check first to rule that out before you start looking for vacuum leaks. I have added some photos, this will give you some ideas, as where to look for them. Most of the time vacuum hoses do get weak on them, either sucking together or leaking, causing some stuttering in the throttle response. I hope you find your problem.

 

[5150jim]

backyardtrouble » Sun Jul 19, 2015 2:12 pm[/url]":dmj2stsq]
Sometimes a vacuum leak can do that, or maybe a good sync check first to rule that out before you start looking for vacuum leaks. I have added some photos, this will give you some ideas, as where to look for them. Most of the time vacuum hoses do get weak on them, either sucking together or leaking, causing some stuttering in the throttle response. I hope you find your problem.

TNX for the pix & yes, I'll have to check the carb sync.
And thank you because I hope I find the problem also. Still getting use to the new bike & 2 more cylinders. :smilie_happy:

 

[RussL]

my 90 GL1500 had the same problem... my mechanic found vacuum leaks in several spots around and under the carbs... replaced most of the vacuum lines and then synced the carbs... fixed the problem...