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Main Area => General GS500 Discussion => Topic started by: Johnsoir on September 16, 2015, 11:27:12 AM

Title: 1996 Running Rough Again
Post by: Johnsoir on September 16, 2015, 11:27:12 AM
At the end of August my '96 GS500 started to run really rough and didn't have the pull I was used to. I took off the carbs and opened them up to clean them. During the procedure I found something in one of the pilots and cleared it out.

I put the bike back together and it ran perfectly. I didn't have time to take it out for a ride so I turned her off. I came back about 3 hours later to find that I had left the petcock to prime and flooded just about everything, the carbs, the airbox and the left cylinder. I drained everything out, pulled the plugs and dumped as much fuel as I could out, let it sit with the plugs out for a while and then came back and put the plugs in and started it.

It ran great still. But by this time again it was too late to go for a ride and I was exhausted.

The next day I took it out was maybe 5 days later, started great, ran fine. But only for about 0.5KM then it just start bogging down and running rough, I pulled over and shortly after it died and I couldn't even get it to turn over. Battery seemed like it was dead. I got it back home and sure enough it was dead.

I charged up the battery, and after starting again ran rough. I figured I must have fuel in the oil. Today I did an oil change and it will start great, run for about 1 minute great and then start to bumble. No backfires, but it just doesn't seem right, choke does nothing but make it stagger more at that point. It doesn't die, just runs .... off.

Any ideas?



TL;DR

Ran rough: cleaned carbs
Hydrolocked it: drained fuel
ran rough: battery died: charged battery
ran rough: oil change
Still runs rough: ???
Title: Re: 1996 Running Rough Again
Post by: junior1786 on September 16, 2015, 11:33:02 AM
Is it running rough through all the RPM range? or just at a certain engine speed?
Title: Re: 1996 Running Rough Again
Post by: Johnsoir on September 16, 2015, 11:39:30 AM
Runs rough At idle and just above, seems to clear up after a bit of throttle has been given but I have yet to actually take it on the road.
Title: Re: 1996 Running Rough Again
Post by: junior1786 on September 16, 2015, 11:52:39 AM
i would start with removing the diaphragm covers to make sure the needles sits correctly and it didn't come loose,  make sure the little o-rings are in place.
Rough idle may require some adjustment to the idle screws.
Title: Re: 1996 Running Rough Again
Post by: Johnsoir on September 16, 2015, 04:11:13 PM
Pretty sure the carbs internals are good, though its not in the realm of impossible. I Re-adjusted the air/fuel mixture screws from 2.5 turns out to 2 turns out and it idles much nicer, took it out for a quick spin and after a few minutes the revs would hang when i came off the throttle.

I'll have to dink around with it some more on the weekend, but that does seem to be bettering the issue.

Thanks for your input junior!
Title: Re: 1996 Running Rough Again
Post by: junior1786 on September 17, 2015, 12:23:14 AM
You welcome :)
As for the hanging revs, i would check the carb boots, if the rubber dried out, it could draw air from the outside, making the mixture lean, and this may cause the revs to hang when the bike is hot.