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Main Area => General GS500 Discussion => Topic started by: badshow13 on July 19, 2017, 06:39:12 AM

Title: HELP! 98 gs500e tough starting after ride
Post by: badshow13 on July 19, 2017, 06:39:12 AM
hey guys i have a 98 gs500e with 4k miles on it... i recently made a post regarding that i could not open the throttle while bike was running and when i did open throttle bike would kill out... well come to find out i had a small leak at my manifold boots and the rod inside the carbs that activated the choke was staying engaged..... now the bike idles and i can open the throttle... i took it for a test drive and as i was coming to a slow turn the bike died off on me in 1st gear.... after about 5 minuets of trying to start it, finally it fired up and i began driving it back home... well same thing when i pulled into my drive way and slowed down bike killed off... anyone have any advice i should try.... now let me remind that i did have the carbs synchronized but that was when the choke level was staying engaged internally.... so now that this is not happen could it need to be re- synced since it was done when the choke lever was engaged? or is there another problem? please help thanks.
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: ajensen on July 19, 2017, 06:46:58 AM
Carb sync should not affect starting that much. I'd look at the spark plugs the next time you have the problem. See if the plugs are wet or dry and go from there.
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: badshow13 on July 19, 2017, 09:23:33 AM
so carb sync will not affect this even though it could have been synced while the choke was engaged? different air flow? if not what else could be the cause? i will try the spark plugs and put new ones.  with that said, it started and ran and i drove it accelerating to 40 mph then when i slow down it killed off... happened twice? spark plug being main culprit? any other advice while im at it again tonite? thanks for the quick response
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: mr72 on July 19, 2017, 09:59:42 AM
Sounds like a vacuum problem to me.

But it could be a dozen things.
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: Shift-E on July 19, 2017, 10:23:33 AM
Try running the bike on reserve or prime. If it runs better, it may be a vacuum issue with the frame petcock. I just dealt with this issue on my bike.

be careful not to leave it in prime though, in case the floats are stuck. The gas will travel through the carbs and pour out of the air box and also into the engine...
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: badshow13 on July 20, 2017, 11:47:39 AM
it does these conditions with or without the vacuum on the petcock... meaning if i run it on reserve or prime or just use a gravity feed through line it does this.... and suggestions on where to put the mixture screws they are currently 3 turns out and the plugs have black soot on them. i sprayed around seals and o rings and manifold and nothing changed in idle.
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: Watcher on July 20, 2017, 11:56:32 AM
Make sure your choke isn't still sticking open.

Send the screws all the way in to make sure they're starting at zero, then go out 1.5 and see where that gets you.
Title: Re: HELP! 98 gs500e tough starting after ride
Post by: mr72 on July 20, 2017, 01:33:43 PM
Quote from: badshow13 on July 20, 2017, 11:47:39 AM
i sprayed around seals and o rings and manifold and nothing changed in idle.

That's not a definitive test for vacuum leaks. And if you sprayed carb cleaner, you know it can (and often will) degrade or eat up rubber parts, right? If it gets sucked into a vacuum port and winds up on one of the rubber diaphragms it can easily create a hole.

Sounds like you are running rich. The o-rings on the pilot needles (adjustment "screws") could be shot, causing it to run rich no matter what you do, and this would cause poor starting when hot.

Or, like I said, it could be a dozen other things. I'd break the carbs down and clean everything, run wires through the orifices, replace ALL o-rings, verify the diaphragms are in perfect condition, replace the intake boot o-rings, inspect the intake boots for cracks, and then start with a known good state with all of this. Troubleshooting this is more complicated and time consuming than just kind of shotgun fixing everything proactively, IMHO.