Frustrated and can't find out what the problem might be! please help!

[mtn.biker93]

Hey guys,

So I've had my 91 gs500 for a while now and have loved it. There has been a persistent problem for a while that I can't understand. The first time I brought it to the shop they replaced the Ignition control (sorry if thats not what its called) because of water damage. The second time they fixed a couple pieces in the alternator. The problem that always seems to come back, is what I think is either carbs or the petcock from what Ive read. When I start the bike up, it idles very very low, and sometimes bogs out and dies. After I run the choke for a while and get it to regular driving RPM's, its good for just a little while. At either higher altitudes or after Ive been running for a while, it starts to sound like its straining hard and then slowly bogs out, dies and won't start up again until I let it sit for about 30-45 minutes. Even then, It really will only last getting me home if that. This has rendered it virtually unrideable and I want to get back on the road! Im just worried about bringing it to another shop and paying hundreds to have them not fix it. Any help is greatly appreciated!!!

[The Buddha]

Ignition control ... water damage !!!

You need to find a new mechanic, this one is a stupid crook.

You probably have a carb or a fuel flow issue. How do the carbs look ... and no, you can not take it to a mechanic any more. Open up and look, anything you screw up, can be unscrewed for 20-40 bucks ... just dont be a ham fisted Idiot. We'll walk you through the rest.

Cool.
Buddha.

[mtn.biker93]

Thanks man! I really appreciate it. I see a few carb cleaning how to's in the sticks, Which do you recommend following?

[yamahonkawazuki]

carb cleaning is EASY. sounds intimidating at first. now by cleaning im NOT talking about the spraycan stuff. what im talking about comes in a 1 gallon can. strip the plastics and rubbers off of it. ( nothing but metal) dunk each one for 12hrs plus. ( normally i use 24hrs.)theyre good as new:) and perform like it.

[The Buddha]

Please dont use that crap. Mechanical clean with wd40 or penetrating oil spray. Toothbrush and e;bow grease.
Cool.
Buddha.

[X-ray]

Ah. Opinions and options.   

[adidasguy]

Funny - water damage to the ignition control which is a sealed electronic unit and under the seat - away from water.
What parts are there to fix in the "alternator"? We don't have one (or do we?). There's the stator and the magneto.

When you clean the carbs, use a can of air to blow out all the passages. There's more to carbs than just the jets. Lots of passages to get clogged. Remove the choke (aka starter circuit) parts and clean those passages, too.

Bogging down after riding a while could be electrical related, if the battery is bad and the system is not charging it up. Low voltage will result in weak or no spark and mimic fuel starvation (I know - once I rode and forgot to connect up the regulator so I rode until the battery went dead). Use a volt meter and monitor your voltage. It is easy to check out the electrical system. Sometimes the regulator goes bad or gets flaky and dies when it gets hot (from riding a while).

[Blueknyt]

its an Alternator with a stator and a rotor, the diff being is the rotor is perm magnets where as a car alternator is generaly the rotor is an electro magnet powerd by brushs and slip rings on the armature.  our stator is a 3 phase AC current generator, the regulator/rectafire converts the juice to DC Via diodes and drops the voltage.  the 3 wires coming out of stator cover can cook the plug sometimes causing issues with charging.    as to ignition issue, the box is electronic and while rare can fail due to spikes in current from a faulty charging system. mainly when the diodes start going bad its possible that unregulated AC current can bleed to the rest of the system causeing havok.   

his more pressing issue seems to be more of a fuel/vacuum flow issue.  be it vent blockage, float adjustment, petcock/screen issues.   i would start at the tank checking lines for kinks or pinches, perhaps pull the tanklines and check flow rates to feeding the carbs.

[fetor56]

When u start it next time & it begins to bog down open the fuel cap & see if that makes any difference.

[Erika]

When u start it next time & it begins to bog down open the fuel cap & see if that makes any difference.

+1 on the fuel cap check. I had similar bogging and dying issues and thought it was the petcock or something electrical. Come to find out, the vents in the cap had crud in it and once I cleaned it out... no more bogging issues at all.