Lots of GS500e Problems

[Youngkidoldbike]

Hello. So I have run into many problems on my 1990 gs500e. Any advice on any? 

Bike revvs up by itself every 10-12 seconds. 

Idles very very high.

When i rev, it takes a long time to go back down in RPMs. 

Black smoke when revving. 

Other than that everything is perfect. 

carburetor is rebuilt and everything is set perfect. I did a bench sync but not a professional carb sync which is probably the problem. but please give input. seems like a vacuum leak to me but i haven't been able to eye it down, plugged the one vacuum line i found and it does fine, but i checked the boots on each side and they are okay. sprayed carb cleaner and it did nothing on any of the boots. So i'm assuming i just need a professional carb sync. Please give in all the input possible 

[arnout]

Black smoke = over rich mixture. Perhaps the choke is stuck on?

High revs and slow return to idle would point to a lean mixture though..

Bench synchronizing should be close enough for an OK running engine and should not result in said symptoms if indeed done correctly.

As far as leaky rubber manifolds go I'd say check manually (remove parts for closer inspection) but for now the carb cleaner/WD40 spray trick should suffice. Especially as you plugged "the one vacuum line" which raises some questions. What line exactly? The hose to the vacuum controlled fuel tap? The vent hose connected to float bowls is supposed to be left dangling open!

[Youngkidoldbike]

Hello arnout. Took the carbs out and found out the problem. The main jet was screwed in on the right carb but the pilot jet wasn't screwed in at all and it was causing a way too heavy flow of fuel and it was coming out the manifold and it's all fixed and i screwed the jet in and everything works perfect!!

[arnout]

On 17/02/2018 at 6:47 PM, Youngkidoldbike said:

Took the carbs out and found out the problem.

Cool. Thanks for reporting back.