Quote from: mr72 on March 01, 2017, 01:41:45 PM

Quote from: nuclearfenix on March 01, 2017, 11:24:30 AM
how much do you guys think a shop will charge me to fix it.

If you just ask them to replace those o-rings and nothing else, probably an hour of labor whatever that is. $80?

If you ask them to fix it which would include diagnosing whatever is actually wrong with the bike and remedying it, I'd bet a competent shop would do it for $200, including replacing the o-rings you supply as a customer-requested fix regardless of whether they think it needs it.

Make friends with someone on this forum and I bet you can get it done in a half hour for nothing. If you rode the bike to my house I'd walk you through it and be done in a half hour. You will spend most of your time removing the tank and airbox, then reinstalling them.

...Hey, buddy! 

$200 isn't that bad. I actually did try looking for someone local on the "Map yourself" thread but it doesn't seem there are many people in VA. Even at that, the one guy I did get in contact with doesn't have his GS anymore and not a lot of experience mechanically on the GS.

So I got the time to remove the airbox and the carbs just to get to the boots. I popped them off and removed the O-Rings (The rings weren't cracked but they were hard as hell, like really stiff), put the new O-rings in and put the bike back together. Took about 2 hours. I warmed the bike up and rode it. Turned the choke off and the RPMs plummeted  to around 1k. Adjusting the idle causes hanging or too low of an idle. I cant get it to 1.5k solid.

I will say that the bike seems to run just fine if I leave the idle at 3k. When ever I sprayed carb cleaner on the bike to find the leak (Before replacing the O-Rings) the only area where I got a response was the boots.

Here are some pictures of the boots before I replaced everything. Ignore the red stuff, it's RTV.

http://imgur.com/GnnXkPh

http://imgur.com/BymYJJ7

http://imgur.com/aM2mbyw

The last picture shows a little crack but it wasn't even all the way through, it was just a surface crack.

What else can I look for before I put it into the shop.

Do yourself a favor and don't spray carb cleaner on it!!!   it can literally MELT the rubber diaphragms that the carbs depend on to work correctly.

Anyway, sounds to me like your problem is the idle mixture is way too lean. Are the access plugs removed on the bottom of the cabs? If so then you should adjust the carbs according to numerous instructions available here but basically the idea is to get the bike FULLY WARMED UP (ride on the road for 10+ minutes) and then tinker with the adjustment screws, start with 2.5 turns out and keep turning out (richer) until the idle speed stops increasing, double-check the hanging idle conditions by revving above 5K rpm and letting it drop, if it hangs at a high idle speed for a few seconds then make it more rich 1/4 turn at a time for both carbs until it stops. If it takes more than 3.5 turns out then you probably need to jet up to #40 pilot jets. Seems most GS500s run best on #40 pilot jets with about 2.5-3.5 turns out, according to reports. Talking about 89-00 bikes here. IDK about the 01+.

Once you get the idle mixture dialed in, adjust the idle speed to 1100-1300 rpm. Anecdotally speaking my bike idles at about 1300+ rpm when it is sort-of-warmed-up (say, 8-10 minutes riding) and after it is seriously warmed up (30+ minutes riding) it tends to idle down at about 900-1000. If I lower the idle any more to try to get the not-seriously-warmed-up idle down under 1300 then it will try to stall when it's seriously warmed up. So there's like this balance you might wind up having to achieve. It's carburetors. Hardly an exact science.

If you have a vacuum leak, or if there is any chance whatsoever you have a vacuum leak, then adjusting the idle mixture is a fool's errand. Fix the vacuum leak first. Same for if you have bad float level or leaking o-rings inside the carbs. Basically idling is very hard for the carbs to do, and it will only do it right if everything is working >95%.

Your idling problem sounds almost exactly like mine was when I got the bike. I would up changing carbs but the fact is all o-rings were hard/cracked/etc. inside the carbs and it had about a half dozen vacuum leaks. Made more sense to start with something more likely to work. In the end I could have made the original carbs work with the same amount of effort but now I have a set of spares But the point is, this is kind of ordinary behavior with long service life. If your intake boot o-rings were hard then you can bet the rest are.

Anyway if the bike will idle at ~1K rpm as-is and you want to sell it, then I'd say let it idle at 1K and sell it, warn the next owner that it probably needs o-rings in the carbs and be done with it. It is only like $10 worth of parts but if you're selling the bike, might as well let someone else do the work. Worst case is it runs but once fully warmed it won't want to idle so you will have to nurse the throttle a little bit to keep it running. Like I say, this is what mine did. It would either idle at 4K or stall. I bought the bike in that condition, confident I could fix it. I eventually did but it took a lot of commitment.

Good luck, and I hope you change your mind and keep the bike

It's definitely running lean. And adjusting the idle screw is pointless, as adjusting it will either cause a hanging idle or drop too low. When it's sitting idling the idle speed tends to just jump around between 1000 and 1400. At this point I have no idea where the Vacuum leak is coming from or even if there is one.

So you're saying a bad float level or carb o-rings can cause the sporadic idle, Hanging idle, and stalling when coming to a stop?

Quote from: nuclearfenix on March 06, 2017, 04:34:06 PM
It's definitely running lean. And adjusting the idle screw is pointless, as adjusting it will either cause a hanging idle or drop too low. When it's sitting idling the idle speed tends to just jump around between 1000 and 1400. At this point I have no idea where the Vacuum leak is coming from or even if there is one.

So you're saying a bad float level or carb o-rings can cause the sporadic idle, Hanging idle, and stalling when coming to a stop?

By "idle screw" you mean the idle SPEED adjuster, right? Just set it so it idles inthat 1000 and 1400 rpm range and sell the bike if that's what you are planning to do.

Yes a wrong float level or bad o-rings in the carbs can and will cause inconsistent idle. It's running lean, that's why you have a hanging idle. Why it's running lean could be any number of things. You can't diagnose mixture (or fix it) until all vacuum leaks are fixed. So unless you have the patience to work this out by tearing down the carbs and replacing o-rings, set float level, maybe re-jet, then work through the mixture setting, then I'd say your best bet is just to make it run in the range of normal and sell it.

Again I am predicating my input based on your previous statements that your intent is to just get it running well enough to sell. The factory spec is idle 1100-1300 rpm and IME even on my properly running GS500E the idle speed varies from 900-1500 depending on engine temperature (but it doesn't fluctuate while running... it just gradually goes down as the engine warms up). My point here is that a variable idle from 1000-1500 rpm is not really a super bad thing.

If you're going to keep the bike then I'd say get a set of o-rings on hand, new jets +1 sized (at least a pilot jet) and pull the carbs again, put a couple of hours of tinkering time into it and you'll probably wind up with a bike that runs right on the money.

As a point of reference, when I had the top-end rebuild done on my bike the shop mech forgot to hook up the vacuum line from the petcock to the carbs. The first thing this did is cause the bike to die after I rode it about 2 miles, I had to put it on prime. But once I figured out what happened of course then it idled all crazy because it had been adjusted with the vacuum line not connected so it had a huge vacuum leak. The idle mixture screws were zero turns on one carb and 1/2 turn on the other. To get it to run right required about 3.25 turns out on both carbs and that's with #40 pilot jets. Then over the course of about 200 miles of riding I tweaked on the idle speed about 1/8 turn at a time while at stop lights etc. before settling on a setting that results in no hanging idle and no stalling. It's a quirk of old carbureted bikes, I guess. Let's call it "charm". But it requires you to be willing to sort of get to know it in this way to make it run right. There's no way the shop could have done this unless the mechanic commuted to work every day for a couple of weeks on my bike. This is an owner's labor of love. If you're selling, don't bother. If you're keeping, then get set for this kind of relationship with the bike. A fuel-injected bike won't require or benefit from this kind of involvement. It'll either run right or not, and if not then you have to replace parts, not adjust things. That's a whole different kind of interaction with the machine.

I'm using BUNA o-rings. I also have an 07 and I can tell you that you'll eventually need to replace more o-rings as you go along. My intake boot o-rings were very dry and flat. My valve needle seat o-rings are jammed with white fuel crud, causing fuel to slip by and rich mix. My main jet o-ring were flat, dry, and packed with white crud. My bike actually ran pretty good before I replaced them, but after i did i was surprised, it's much tighter. I wouldn't have known how much better it could run until I did it. Luckily, folks out here sent me to this guy, who sells rings for pennies. I paid about $10 with shipping for everything I needed: http://www.thisoldtractor.com/for_sale.html