1983 GS 450 ED Revving problems!!

[cpadovano0261]

Hey Im recently new to this site and I have a question about my gs 450. About two weeks ago I got a 1982?-83 GS 450 ED. The bike only registerd 10,000 miles on the odometer and seeing as how clean the bike is it seems believable. It had been sitting for over 10 years in a barn with the same gas in it. So I took of the carbs off and cleaned them all the way through, the main jet, pilot jet. I drilled out the caps that cover the air screws and blew every line making sure air and carb cleaner came out the other end! Also the whole choke circuit was blown out. There wasnt a trace of old gas in them after I was done. So I put them back on. After that I took some new gas and sloshed it around in the tank and drained it. I hooked it all back up to the carbs, and I tried to start it and after a couple cranks it fired right up. The motor sounds great and has a smooth idle...however when I give it any gas it bogs down, and some times dies. The highest it revs is 3000 rpms it wont go past that.
Since then I have taken the carbs off and on like 10 times to make sure they were clean and that everything is flowing correctly. Ive checked the compression and its great. The spark is great to the spark plugs...it gave me a nice jolt.lol The slides in the carbs respond to vacumn and everything. The only thing I can think of is if maybe the advancer is bad. Does this year bike have the spring advancer or is it an electronic advancer in the igniter box? If any one has any suggestions please let me know...ill try anything!! Im stumped...

[BassCliff]

Greetings and Salutations!!

Hi Mr. cpadovano0261,

Your bike needs the airbox properly sealed and a clean, lightly oiled air filter installed. You should replace the intake boot O-rings, and maybe even the intake boots themselves. You also need to do a proper cleaning of the carbs. I know you've squirted them but each carb body really needs to be soaked in a chem dip (Berrymans') for about 24 hours apiece. Your pilot circuits are still plugged. It's all in your "mega-welcome". Let's get started.

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", the Carb Rebuild Series, and the Stator Papers. 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.

Thank you for your indulgence,

BassCliff

[spwalker09]

Just curious, why did you drill out the air screws? Could that be the reason why the bike is running so bad?

[BassCliff]

Just curious, why did you drill out the air screws? Could that be the reason why the bike is running so bad?

Hi,

I'm hoping Mr. cpadovano0261 meant that he drilled out the CAPS for the idle MIXTURE screws so that he could remove/clean/adjust them. They also have a little O-ring that must be replaced.




Thank you for your indulgence,

BassCliff

[spyug]

Sounds like a combo of problems to me. Mixture screws and carb balancing and maybe leaky o-rings.

Did you remove the airscrews and clean that passage? Were the o-rings ok or replaced and how many turns out?

As for carb balancing I'll guess that you bench synched them as per the tutorial but did you perform a vacuum synch? If his is not done you will likely only have one carb working efficiently and the engine is going to balk when you twist the throttle. You will need a manometer for this so beg borrow, steal or make one if you don't already have one.

As Mr. Cliff says, If there is any air infiltration you will have similar types of issues so make sure your o-rings are replaced ( including those on the head to intake boots) and your airbox is properly sealed if you run one.

Carbs can be a PITA to get right but problems are dirty jets and passages or air infiltration. Balancing is crucial to get them optimised but you can't achieve that if their not working correctly first. Look to the o-rings.

Good luck and let us know how it turns out.

Cheers,
Spyug.

Welcome aboard by the way.

[cpadovano0261]

Yea I drilled the caps out covering the air screws, clean the passage way and set them at two and a quarter turns from the needle seat. The O rings were not replaced but they did not look bad at all...ill try replacing them though. Also I did not perform any sync on the carbs! I don't know how to do that but ill check out the carb cleaning tutorial. What are the vacumn screws for? Do they control the vacumn pull on the slides? P.S. where can I get all the stuff to rebuild these carbs? Thanks for all your guys help I really appreciate it!

[Calvin Blackmore]

Hi,

I'm hoping Mr. cpadovano0261 meant that he drilled out the CAPS for the idle MIXTURE screws so that he could remove/clean/adjust them. They also have a little O-ring that must be replaced.




Thank you for your indulgence,

BassCliff

yeah does anyone know of robert barr sells the itty bitties?
27 yrs is old for anything metal not to speak of rubber.

[BassCliff]

Yea I drilled the caps out covering the air screws, clean the passage way and set them at two and a quarter turns from the needle seat. The O rings were not replaced but they did not look bad at all...ill try replacing them though. Also I did not perform any sync on the carbs! I don't know how to do that but ill check out the carb cleaning tutorial. What are the vacumn screws for? Do they control the vacumn pull on the slides? P.S. where can I get all the stuff to rebuild these carbs? Thanks for all your guys help I really appreciate it!

Hi,

It's in your "mega-welcome", links to to purchase Rober Barr's O-ring kit and to The Carb Rebuild Series.

Thank you for your indulgence,

BassCliff

[spchips]

If it's an idle mixture problem, then you should be able to ride around the block on choke with the engine racing and once you are moving with high RPM's everything will seem normal.

Also..... Valve adjustment, valve adjustment, valve adjustment, valve adjustment!

-Sean