I did a search and found some ideas of what the problem might be, but I didn't want to bump the thread from 2003 haha. Here's a bit of info about my issue.
I can start the bike up and as long as I don't touch the throttle, it will idle perfectly but as soon as i remotely touch the throttle, it hops up to 4000rpm and stays there. If I shut the bike off and turn it back on, it will sit at idle perfectly until the throttle is touched.
Also, the bike is running considerably lean by the look of the plugs. The bike is 100% stock except for a K&N drop in filter in the stock airbox.
I had the carb bowls apart and cleaned them all up and put on new o-rings.
From the search I found a couiple reasons why this could be happening, they are:
"floats are sticking, or debris is getting inbetween the float needle and the seat causing to stick open (oh, I just said that), or the float height needs to be adjusted."
"carbs are out of sync"
I installed a brand new throttle cable, lubed it and i can hear it snap shut when I left off the throttle so it does not seem to be sticking. Also, because the bike idles perfectly I did not adjust the idle screw because it seems to idle spot on.
Anyone ever run into this problem recently and found a cure for it?
Thanks in advance,
Andrew
You have a vacuum leak. You must find it. If you're lucky, you'll be able to find the leak by starting the bike, then spraying the carbs and intake tubes down with starter fluid. Once you hit the leak, the bike will rev up a bit and you'll have found the leak. Don't forget to check the petcock too, since it is a vacuum operated item and could be leaking. Once you find the leak, you'll know what to do. My project bike had a big vacuum leak because the intake boots were cracked...
I think Fred is probably right, but one other (slim) possibility is a binding throttle cable. It is simple enough to check and a LOT easier to fix. Looking at the carbs, be sure that the cable is returning all the way when you let off the throttle.
I'm with fred...but
Starting fluid is potentially explosive so if you use that, be careful. There are safer options. You can use pretty much anything and the rpms will change when you hit the leak. WD40 or carb cleaner are what I use.
That's just my 2 cents.
Starter fluid is super flammable, but when I did it I didn't have any trouble with fire. The problem with things like carb cleaner and WD-40 is that they're a whole lot less flammable now than they once were. The less flammable the spray you use, the more subtile the change in RPM will be and the harder it will be to find your leak. Starter fluid is a pretty standard thing to use when diagnosing vacuum leaks. My friend who used to work as a British car mechanic told me his shop used to buy it by the pallet. Just be careful, do it outside and don't smoke or anything crazy like that while handling the super flammable spray.
you may just need to do two major things. GS's were notorious for coming from the factory with lean jetting. contact Buddha for some larger jets and they should really help with this issue. be sure to specify what year your GS is too.
Thanks for all the help guys, i'll take a look over the bike for vacuum leaks. I know for sure the throttle cable isn't sticking, I can hear it hit the stop shut when I release the throttle
Andrew
Just to confirm, should the right side vacuum port we capped or left to atmosphere? I've heard both
Thanks,
Andrew