1980 GS450 Carb sync

[apopleptic]

Hello, I am working on my GS450 and am looking to sync the carbs.
The issue I am running into is that the instructions in the repair manual say to turn the air screw, but it says that in 1980 there was no air adjustment screw and when I look at the location noted in the diagram there is just a small pinhole on both carbs and neither has a screw.
Can anyone please shed some light on this?
Thank you.

[cowboyup3371]

Welcome to the site. I would bet those are plugs covering the mixture screws mandated by the EPA so you couldn't mess with them. They can and should be removed. Is this bike new to you? Have you recently cleaned the carbs?

Basscliff will come by later with the official welcome but in the meantime, why not put your bike info in the signature block and your location in your profile. Plus, we'd love to see some pictures when possible.

[BassCliff]

Greetings and Salutations!!

Hi Mr. apopleptic,

You just might want to clean those carbs properly and install a new set of O-rings. There is a "how to" guide on my little website.

Let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed. I will put you on my prayer list.

Thank you for your indulgence,

BassCliff

[apopleptic]

Welcome to the site. I would bet those are plugs covering the mixture screws mandated by the EPA so you couldn't mess with them. They can and should be removed. Is this bike new to you? Have you recently cleaned the carbs?

is there some trick to remove these plugs without damage?

Thanks for the welcome, I have had the bike about three years and its my first bike.
Pretty much each year I have one issue or another that prevented me from riding it much without some working on it. I've probably only put about 300 miles on the bike since picking it up.

I have had the carbs all apart and they are pretty much spotless inside. no dry rot or anything anywhere except the fuel line which I replaced.

FWIW, I've been trying to keep this repair budget down as low as possible. so far my only major replacement was the igniter and the rear tire.
I'll upload pics once I get some current ones.

[cowboyup3371]

Go to Basscliff's page and open up the carb rebuild tutorial from Nessism in there. It will explain all that is good with fixing them up to include how to remove that cap. Don't take any shortcuts or you'll be doing the whole thing all over again...TRUST US on this.

[apopleptic]

good info in that tutorial, almost exactly what i thought would need to be done to remove the plug.
I'll let you know how it turns out.
Thanks again

[BassCliff]

Hi,

On my little website there is a tutorial specific to the 450 carbs. But Mr. Nessism's guide is pretty much all-inclusive in its scope. There's also a guide on how to post pictures to the forum. Keep us informed.


Thank you for your indulgence,

BassCliff

[apopleptic]

I looked through both tutorials and have removed that cap as the instructions indicated. seemed like there was a little bit of funk underneath one of the caps and I wonder if thats whats gumming up. Tomorrow I'll see if I can follow through all the steps in the rebuild, most steps have already been done, so I get what was said about reading the instructions beforehand.
so far prior to this I've gotten the bike started, idling, and running well enought to ride around with no real issues on short local trips, whats I've noticed is that once the RPMs get to about 5K the bike hesitates and then runs choppy and the RPMs wont really go beyond 7K.
My goal is to have this bike ready for a cross country ride in the next month or so, so expect alot more silly questions in the next few weeks!

[pete]

Welcome to the forums! Seems you're already in good hands here, but let me just share one more link with you that is in amongst all the awesome goodness that is BassCliff's site:

http://www.cycleorings.com/

Go there and get the complete combo kit for the 450 carbs, you won't regret it.

[apopleptic]

Welcome to the forums! Seems you're already in good hands here, but let me just share one more link with you that is in amongst all the awesome goodness that is BassCliff's site:

http://www.cycleorings.com/

Go there and get the complete combo kit for the 450 carbs, you won't regret it.

I did as suggested, even though I'm pretty sure the intake o-rings are good, I bet the rest of them aren't.
I'll keep everyone posted on how this turns out, or if I have any other questions on this topic. Mean time I will go bother you all in a new thread

[apopleptic]

is there a trick to get the pilot air screw out? I have unscrewed both all the way but it does not want to come out of the hole.


EDIT: I was able to remove one of these using a drop of hot melt glue on the end of the screwdriver. the other one is still stuck in there

[cowboyup3371]

Probably need to use some PB Blaster and let it soak some.

[pete]

The O rings tend to stop them coming out that last mm or two, so I ended up using a small jewellers flat head to sort of lever it out.

[apopleptic]

The O rings tend to stop them coming out that last mm or two, so I ended up using a small jewellers flat head to sort of lever it out.

This is what did it, what a pain in the butt...

I will say that the inside of these carbs is spotless. You could eat off of it, if you eat gasoline.

[pete]

So he cleaned them, but didn't replace the O rings? That's insane... why would you go to all that trouble and not replace them? Bizarre...