81' GS650G Idle issues.

[krowe985]

recently took my carbs off and cleaned them, and at first i couldn't get it to idle, now i have it idleing at just over 1000 rpms, but when i rev it the rpms drop slowly, any advice?

[BassCliff]

Greetings and Salutations!!

Hi,

Have you put the airbox back on yet?

Welcome to the forum!

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

[Nessism]

No lube on slides please, but yes on changing the intake boot O-rings to avoid air leaks, and yes on adjusting the pilot screws and performing a vacuum sync.

[BassCliff]

No lube on slides please

Really? Hmmm, I wonder where I heard that?

OK Ed, I'll edit my post above so that I don't steer anybody wrong. Sorry and thanks!


Thank you for your indulgence,

BassCliff

[spchips]

Assuming it's stock, and everything is in place (these bikes won't idle right unless the carbs and airbox are fully assembled, including the cover. Don't forget to cover the #3 vacuum port if you are doing trials with the tank off.

I'd suggest you are either a little lean or the valves are out of adjustment.

The leanness is probably coming from an air leak. check all those boots, etc, and go from there. Valves help stabilize the idle tremendously. If you have been playing with your air screws (the little ones on top), this could be the culprit.

[krowe985]

yes, it is fully assembled.

[krowe985]

Assuming it's stock, and everything is in place (these bikes won't idle right unless the carbs and airbox are fully assembled, including the cover. Don't forget to cover the #3 vacuum port if you are doing trials with the tank off.

I'd suggest you are either a little lean or the valves are out of adjustment.

The leanness is probably coming from an air leak. check all those boots, etc, and go from there. Valves help stabilize the idle tremendously. If you have been playing with your air screws (the little ones on top), this could be the culprit.

yes, i did lower all 4 air screws to the bottom then one complete turn upwards, when i got the bike, the air screws where roughly half way up, the previous owner had a 3m puffer pad stuffed in the air box that he was useing as the air filter, it was very constricting, the cage for the air filter is missing, and was missing when i got the bike, it now has a good air filter in it. when i cleaned the carbs, all i did was take the float bowl off, left the jets and floats attached, and sprayed with carb cleaner, then soaked in carb cleaner for about 45 minutes, then air blew everything, then let them dry a little, and i took the needle and top part of the carbs off, and i didn't dissassemble the needles, and did the same with the needles and diaphrams as i did with the carbs, the only thing i adjusted was the air/fuel screws.




edited: it does run perfectly now, except the idle issue, when i lower what i belive to be the idle screw at the bottom back side of the carbs ( i call it the butterfly stopper) it revs properly, and the rpms drop like they are supposed to, but it doesn't idle, but if i adjust it up, it will idle properly but it takes a while for the rpms to drop back down. and the throttle does pop back to place, nothing feels like it is restricting the throttle cable.

[Nessism]

edited: it does run perfectly now, except the idle issue, when i lower what i belive to be the idle screw at the bottom back side of the carbs ( i call it the butterfly stopper) it revs properly, and the rpms drop like they are supposed to, but it doesn't idle, but if i adjust it up, it will idle properly but it takes a while for the rpms to drop back down. and the throttle does pop back to place, nothing feels like it is restricting the throttle cable.

Try opening the pilot screws to 2.5 turns out.

[spchips]

Leads me towards thinking it's time to to a valve adjustment. That should help, and cannot hurt. Based on the PO's "enginuity", he probably didn't spend much time with it.

[1_v8_merc]

Okay, so you're saying, it Idles okay, but when you crank the throttle, the RPM's go up, but slowly come down, or don't come down at all?

If they come down way too slow, that is DEFINITELY gotta be an AirLeak.
I had the exact same problem with my 82 650 just last week!

I took my carbs off last week to check something that turned out to be a false alarm, put them back on, no big deal.

Apparently I didn't have a couple of the rear boots tight enough.....cause my RPM's were sticking pretty bad.
After I tightened them down, the RPM's instantly dropped right away like they should after cranking the throttle.

I had the boots really tight too! But just not QUITE tight enough.....I was amazed at how such so little tightness could affect the RPM's like that!

[krowe985]

ok, i adjusted the air/fuel screws to 2.5 turns up, now it idles properly, and revs up and rpms drop properly,


when driving it, it speeds up properly, but when i'm trying to cruise along and try to stay at a certain speed and rpm, it wants to "Shutter" a little bit, it will periodiclly give a little more power, then drop back down to where i was, like a "Sputter" almost, any ideas?

[krowe985]

*bump*


oh, is bumping allowed on these forums? if it is within a reasonable amount of time after last post and the issue/question isn't resolved/answered?

[BassCliff]

ok, i adjusted the air/fuel screws to 2.5 turns up, now it idles properly, and revs up and rpms drop properly,


when driving it, it speeds up properly, but when i'm trying to cruise along and try to stay at a certain speed and rpm, it wants to "Shutter" a little bit, it will periodiclly give a little more power, then drop back down to where i was, like a "Sputter" almost, any ideas?

Hi,

Did you set the float height? Are you using an inline fuel filter? Did you properly clean the carbs and perform all the necessary maintenance procedures according to your "mega-welcome"? Keep us informed.


Thank you for your indulgence,

BassCliff

[krowe985]

Hi,

Did you set the float height? Are you using an inline fuel filter? Did you properly clean the carbs and perform all the necessary maintenance procedures according to your "mega-welcome"? Keep us informed.


Thank you for your indulgence,

BassCliff

i wasn't a part of the forums when i cleaned my carbs, so to answer one question, no i did not perform all the necessary maintenance procedures according to the "Mega-welcome".

All i did was dissassemble the basic things. I took the float bowl off, and the top where the diaphram is off, took the needle and diaphram assembly out of the carb body but didn't Dissassemble them, sprayed down with carb cleaner spray, soaked for about 45 minutes, air sprayed out crevises, sprayed with more carb cleaner where needed, then air sprayed again, and then let air dry becore reassembleing and putting back on bike. the ONLY thing i adjusted while cleaning the carbs was the air/fuel screws because of the previous owners "Engenuity" with the air filter.

[BassCliff]

Hi,

The maintenance procedures in the "mega-welcome" (above) are guaranteed to usher you into GS nirvana, if you take no shortcuts. Keep us informed.


Thank you for your indulgence,

BassCliff