GS1000 kickin' my AZZ...

[Newbee]

1980 GS1000: 120lbs Compression on all 4,warmed up and dry. Carbs synched. 115 Main jets,200 air jets and ?? pilot jet. Stock air box and exhaust. K&N air filter. 4000ft elevation.

Rebuilt carbs,cleaned electrical connections,installed NOS Signal generator(cause I had one).

Seems to idle smooth. CYL 2,3,4 pipes are about same temp. #1 much cooler, almost cold. If I pull the plug wires while bike is running on either 2,3,4 bike will die or almost die. Pull #1 doesn't seem to affect the idle or anything. Check the plugs after a aggressive 20 mile ride and 2,3,4 are almost white, #1 wet foul or near sooty black. Bike seems to have power issues from about 1500rpms to 4000rpms...anything after that better hold on tight.

Pulled the carbs back off and apart looking for missing pieces,parts or whatever. Checked float height. Even measured fuel in bowls(2 OZ) even in all carbs. I though I detected some fuel in the vacumm line to my petcock..not sure how this would affect anything?

Before I rebuilt carbs I was having fouling problems in 1,2 & 4. Carb rebuild definately fixed alot of my problems but not sure what's going on in #1. Strong spark on all plugs while bike is running. Do I maybe replace the Ignitor and solder all wire connections?

I know I need to re-jet but not sure which jets and what size? Do I just replace the main jet, say with a 120 or do I do something else?

Maybe I should just hop on my KZ1300 and forget about the GS for awhile...

[Black 550 L]

I am having exactly the same problem with my 550. I can't figure it out either. I rechecked the valve clearances yesterday and am thinking about pulling the carbs and looking at #1 this weekend but that doesn't seem like it is it after reading your post. Please if you figure it out post what cured the problem Thanks

[almarconi]

Did you verify that you have spark at plug 1? Check the cap and wire.

Is carb #1 getting fuel, pull the bowl off and see if gas is coming out as it should. Double check to make sure needle valve is clean and operating properly.

When you cleaned the carbs did you dip all of them and then rebuild them?

You mentioned that you synced the carbs but if #1 is not firing you are not going to get a good sync.

Where are your mixture screws set?

You should not have fuel in your vacuum line..is your petcock leaking? If you have a test tank you may want to try this to rule out any petcock issues.

Your probably pretty close to getting it running right..more than likely you need to go back through the #1 carb.

[RJ]

Pull the bowl off of the carb, pull the plug off of the pilot jet, spray carb cleaner into the pilot jet, blow compressed air into the pilot jet, repeat 2-3 times. Next, pull out the emulsion tube and clean out every one of those little holes. If it's the carb that should do it. Of course this is assuming that you're getting good spark, the diaphragm is not torn, and all of your o-rings are new.

[Newbee]

Got a good carb clean

When I rebuilt the carbs..they were dipped a minimum of 24 hrs. Sprayed with carb cleaner prior to dipping and afterward. Completely disassembled. Also blew air through everything. Resealed Air box too. Definately getting spark on number 1. I really don't think there is an ignition problem. I am going to take apart gas tank and completely clean it. New O-rings on the way. Slides appear to function..I checked them without the air box on and the bike running.

I still am sure I need re jetting for my K&N Filter. Just not sure which ones to change or what size to get?

[RJ]

It's probably something fairly simple since the rest of the cylinders seem to be running properly. You've got o-rings in the carbs themselves as well as ones that seal the carb boots where they meet the head. All of those need to be replaced. Also along those same lines, the rubber plugs that go over the pilot jets need to be soft in order to seal properly. If they're not, get some new ones.

[Newbee]

O-Rings ordered

I ordered (2) complete sets from Mr. Barr. I will replace everything. The rubber plugs were already done...I am getting close to get this thing runnin' the way it's supposed to be and learning alot along the way..to bad riding season is about over for me....

[82Shafty]

If I had 3 clean burning cyls and one wet an foul I would first verify there is good spark like mentioned above.

If no spark, and plugs are new, then I would still install another new or known good plug to ensure it just wasn't a dodgey plug.

Then I would check to ensure the boot itself wasn't shot, you could alway switch 1&4 boots to see if the problem follows the boot. If you don't have an ohm meter.


If you have a quality ohm meter (DVOM):

Each cap should ohm out to 5K ohms, almost all of mine were infinite. At 3.60 a piece, it's good insurance.

If you have a monster blue spark coming out of the plug and it is still wet then you are way over fueled on that one cyl and need to focus on the carb.

[RJ]

Yes it definitely is a learning experience LOL! I've been through it myself. One other thought, do you have access to the idle mix screws? They're up top in front of the carbs just before thdy neck down to the part that slides into the intake boot. They are covered with a metal plug from the factory. There is a tiny o-ring in there that needs to be replaced. The screws need to be removed for proper cleaning as well. If you don't see them then the plugs have probably not been removed.

[82Shafty]

Yes it definitely is a learning experience LOL! I've been through it myself. One other thought, do you have access to the idle mix screws? They're up top in front of the carbs just before thdy neck down to the part that slides into the intake boot. They are covered with a metal plug from the factory. There is a tiny o-ring in there that needs to be replaced. The screws need to be removed for proper cleaning as well. If you don't see them then the plugs have probably not been removed.

Don't lose the tiny washer... I got lucky and found a freak washer at the Home Depot... It was a metric washer that wasn't supposed to be in the bag it was being soldin as it was the only one of its kind out of 25 little bags. If I had found more I would have offered some up on here, but there wasn't anymore than the one I needed; I considered myself blessed for the day.

[Newbee]

New idle mix screws

I got them from Capital Karb for $6.00 each..included plug,screw,spring,washer and o-ring. My plugs were alreayd out and I had to ez-out all 4 of the old mixture screws (PITA).

[RJ]

Hey man, how are you coming along?

[Newbee]

Carb problems fixed...YEE HAW or YAHOO is it?

The only thing I can add to all the carb threads is be PERSISTENT and clean and clean some more. DANG!! I smell like a walkin' can of carb cleaner.

Fouling problems gone. Pulls hard to redline, no backfiring at idle or de-celeration. Mileage up from 26mpg to 40mpg. Plugs lookin' good. Synche'd up great and idles nice and smooth at 1200rpm's.

I am running stock exhaust and intake system with the addition of a k&n filter. 200 air jet, 120 main jet, 40 pilot jet and pilot screw 1 turn out at 4500ft elevation.

I wish it weren't snowing cause' I'd be up for a nice long ride.

Thanks for everyone's help. Now I can get on the 1100 project.

[80GS750]

nice job....

so you still had some dirt in them?

[bosshog21]

Maybe a vacuum leak?

Maybe you just may have a vacuum leak.Either at the boot or maybe the screw under the manifold.
Clean the carb out correctly you shouldn't have a problem.
Maybe your valves are open all the time possible maybe either or?
It possible check your valves clearences no compression mean it running thru the cyl in and out .
Do a compression check.
Joe