GS450 idles at 3-4.5k

[Steve]

Now that we have gotten past some of the attitude issues, it comes back to the basics. You have not yet done a proper carb cleaning. All bets are off until that is done, as anything suggested is based on clean carbs. Dropping the bowls and spritzing some spray around what you can see might make it look good, but the parts that NEED to be clean are the little passages that are deep inside the carb body that are only cleaned by prolonged contact with chemicals (carb dip) or the mechanical agitation of an ultrasonic cleaner.

It would also help to know, ... what year is your 450? They changed carbs in '83, so some of the adjustment details are a bit different.

.

[tkent02]

When you clean the carbs, an important step is to ensure all of the internal passages are clear. The one to the choke, the ones to the transition ports, the ones to the mixture screw and the rest of them. One way to ensure this is to take a spray can of carburetor cleaner and shoot it through all of them. Shoot it in the choke where the plunger goes, it should come out through the holes in the choke feed tube. Identical pattern on both carbs. Same with the transition ports, shoot it in where the mixture screw goes, the pattern out the ports should be identical on both carbs. All of the ports and passages should be tested the same way, the pattern should be the same on both carbs with the exception of the vacuum port for the petcock, there's only one of those. Every hole in the carb body leads somewhere.....
You will want to be wearing safety glasses.

[tkent02]

And the ultrasonic cleaner is great, even the cheap one from Harbor Fright will be adequate if you give it a little time.

This one works:

http://www.harborfreight.com/25-liter-ultrasonic-cleaner-95563.html

I don't know if this one will fit a carburetor or not:

http://www.harborfreight.com/ultrasonic-cleaner-3305.html

[Thumper88]

That youtube video is your bike?
That clear tube you have hooked up is the petcock vacuum tube. It applies vacuum to the petcock when engine is running to allow fuel to flow.
You currently have this line venting to atmosphere....

[tkent02]

You currently have this line venting to atmosphere....

I guess that would qualify as an air leak.

[Gorminrider]

You mean this one, Thumper? Good Eye,man!


I told you someone would know! anyways if not need be taken off the list, so good thinking whatever.

[Gambit]

Well, if the vent tube is supposed to go to the petcock, I'm going to assume the tank should be pressurized. If that's true, I need a new gas cap as well, considering the current one just kinda sits there. This is all in my other videos and on my other thread.

And one thing, just for sport......If you don't like my attitude, don't read my posts. Ignoring someone doesn't require a button. Help if you want. I'll stick around and try to share what knowledge I have. Don't help if you want, and I get frustrated, sell the bike, and leave you to your hill of beans. Knowledge is power. Absolute power corrupts absolutely. So share it, or suffer the lonely life of a sith.

[Gambit]

Second thought........Bye.

[Thumper88]

No, the tank is not pressurized. That tube is meant to pull vacuum on the petcock.
The stock petcock is vacuum actuated (I assume yours was either replaced or it is in the prime (PRI) position-always on).
It does not affect tank pressure whatsoever.

Start the bike with your finger over that tube-idle should improve.
You need to either cap off that connection (remove tube and put vacuum cap on the nipple) or replace petcock (if necessary) and reconnect the vacuum line.

[Gorminrider]

just to be clear, "we" (Thumper+me, anyways) are assuming (and hopefully too, because it fixes your problem)the loose tube in the video is this one -#54
your carbs might be ever so different but you will see this port on just one carb of your twin.

[tkent02]

NO he won't see it, long gone. You Sith.

[Gorminrider]

well, I'm glad of the reminder per the vacuum port, in case someone with similar asks again. I forget to ask about the "Obvious"and the Obvious List seems to get longer the longer I own a bike.....sigh-but "Obvious " is not the same for everyone, is it?

[tkent02]

Obviously not, with the number of new guys we get who don't seem to have a clue how anything works and don't seem to want any clues. "Just tell me how to fix it cheap and easy so I can hop on and ride."