1983 GS550ES Fuel Delivery Issue

[Guest]

Hi,

I did order the right side intake just in case but comparing it to the one on there its pretty much in the exact same condition. I also had the air box completely off the carbs to make sure the slides were not being held up by the diaphragm and it ran significantly worse with them off so maybe im wrong here but if there was vacuum leak that bad wouldnt it run about the same? Im just throwing darts at a board here let me know if you have any other suggestions.

Thanks for the help,
Joe

 

[Cipher]

Hi again,

So i checked the throttle response and its pretty much immediately shoots up in the rpms but has a hard time coming back down. There seems to be a good amount of slack on the throttle cable and i can rotate the grip about 5 degrees before the throttle grip starts to catch and open the throttle on the carbs. I checked the choke cables and they both move in and out freely and seem to fully extend. I made sure that they were correctly seated and i put a drop of teflon oil on each to make sure they move really well in the choke slides on the carbs. I turned the air/fuel screws down to 1 turn out and it actually didnt immediately rocket up to 5k Rpms and stayed relatively low in the RPMS (close to OEM idle speeds) and I could even rev the engine and the rpms would come down like you would expect them too. However after about 5 minutes of running the rpms kept going up and eventually after i revved it again the rpms shot up and stayed there like usual. I took the boots off and i ran the bike to look at the slides inside the carbs to make sure the diaphragm isn't holding them up and they were working perfectly. I absolutely doused all the seals in WD40 to see if there was a vacuum leak and i got no white smoke or drop in RPMS. Everything ive checked so far seems to be perfect but something causes the bike to rocket up in the RPMs after it warms up and I dont know what could cause that. Anyways let me know what I should check for next going forward, i appreciate your help.

Thanks,
Joe

If what you've written is true and the engine runs strong and smooth then sadly you have an air leak.
You said you changed the intake o rings? What source did you use?
Did you replace number 23in this fiche? I got mine from member Robert barr and it fixed the exact symptoms on the same powerplant for me.
the difference old to new is shocking in terms of dimension and flexibility.

 

[Guest]

Hi,

Yes i replaced the part #23 o-rings with the genuine suzuki viton o-rings. My dad bought the O-Rings and i think he got them from Suzuki Parts Monster or something? They seemed very pliable when i put them in and i put a drop of oil on all of them when I put them in. They came in a sealed bag with the Suzuki sticker than comes on all their OEM parts. I might try and use a propane torch without lighting it and run it around the seals and everything to see if the engine speed changes to see if I cant find a leak somewhere. Let me know what you think.

Thanks,
Joe

 

[Guest]

Update:

I have no clue what else to try at this point. I ran a propane torch around every single seal and the carbs to make sure its not leaking from anywhere. It isnt leaking at all because nothing about the idle changed. Its almost like its running completely on the main jets when its warmed up. I thought that maybe it was because the pilot circuit wasnt sucking any air and when i took the airbox off to see if those small holes were pulling a vacuum they werent. I sprayed a ton of seafoam carb cleaner into these holes and now they create some suction but it still rockets up to 5500 rpm. It idles significantly better at 1 turn out than it does at 2 turns out even though my problem should be caused by lean conditions by having it 1 turn out should make it super lean and it runs better that way. The only possible thing I could think of is that since the pilot jets in the carbs are size 40 instead of 35 is that when i lean it out to 1 it runs better because it is getting less fuel which would simulate the conditions of the 35 size jet. Considering ripping the carbs apart and soaking all the metal in one of those Berrymans paint cans full of carb cleaner to try and seriously unblock all the passages. If anyone has any other suggestions let me know. Otherwise im going to just keep monkeying with it until i unfortunately have to take it to a shop or sell it. Thanks for all the suggestions again guys.

Best,
Joe

 

[roeme]

(...) Considering ripping the carbs apart and soaking all the metal in one of those Berrymans paint cans full of carb cleaner to try and seriously unblock all the passages. (...)

So when you wrote in Post #1 that you've cleaned the carbs; you didn't mean you had them apart? That would be Newbie Mistake 1B.

Could've saved a whole lotta time.

 

[BigD_83]

So when you wrote in Post #1 that you've cleaned the carbs; you didn't mean you had them apart? That would be Newbie Mistake 1B.

Could've saved a whole lotta time.

I'm surprised this didn't come up earlier in the thread. It's usually point #1 in cases where bikes have come from a previous owner (PO). You'd think that the carbs would be pristine, not having been run in that long, but only if they were empty of gas before it sat.

It's a great idea to run the carbs dry before storage.

 

[BigD_83]

Y

will keep trying on this one. I dread the thought of sending it into the local dealer for a $125 per hour service charge

-joe

Don't, just don't...most shops do not have the time or inclination to put the required work into your bike.

 

[Guest]

Hi,

I have had the float bowls off and took out all the jets to clean them and the passage ways. I didn?t do a complete teardown because I was afraid of ruining a part. I had the hats off too to check the diaphragms and needles. Everything was super clean but maybe I didn?t go far enough.

-joe

 

[Cipher]

Hi,

I have had the float bowls off and took out all the jets to clean them and the passage ways. I didn’t do a complete teardown because I was afraid of ruining a part. I had the hats off too to check the diaphragms and needles. Everything was super clean but maybe I didn’t go far enough.

-joe

Ignore the smug school marms. If the engine runs strong and steady its not dirt as roo.t cause.
Especially if it starts easily.

This carb has no real adjustability except swapping of main jets. The spec is clearly viewable so if they're stock most likely everything else is

Check spark plugs black white or tan?
You do of course have the intake fully assembled. Airbox on, filter installed?

 

[Guest]

Hi Cipher,

Just wanted to drop you a quick update. I turned the air fuel screw down to a half turn out and the bike no longer is ready to rev to the moon. It?s drivable. Obviously I can?t leave it like that so I ordered the size 35 jets to replace the size 40 pilots that are in there now. I don?t know why 40 pilots are in there but the manual says 35 so I?m going to hope that replacing it will fix my problem. I will be back with another update once they are installed but I think I?ve found the problem and it was caused by the engine running way too rich not lean because it only revved high when I got hot. Thanks for the help again.

best, Joe G

 

[rphillips]

The old GS's were pretty cold natured, needed choke to get going even in summer. Many, in my area, would go up a size or 2 on the pilots, just to make them start easier with less choke. I don't remember any adverse effects.

 

[chris]

I agree with rphillips, I don't think the pilots are the smoking gun. The bike might run better with the 40's. Have you done a proper strip and clean of the carbs yet ? Are you absolutely sure that nothing is holding the slides up ? You have a very nice bike, hopefully you can get it running nice.