GS850 carb rebuild help please

[RastaraL39]

Hey all, excellent info here, been reading awhile, first post. Anyway, completed thorough carb rebuild per this site with cycle o-ring kit, bike runs very rough, sputters,-won't idle w/o choke and carb3 has no fuel in the bowl. I have another set of carbs off another 850 that I put on the bike and it runs well actually,got'em synced up etc and rode it-runs well so I know the bike is ok because I did valve adjust etc. Plan on doing coil mod but it runs pretty good so I want input on what I should concentrate on for the poor running carbs. How critical is float height? Why is it only able to run with choke on? I was very thorough so I'm a little perplexed.

[Nessism]

Please check my signature for the Newbie Mistake thread and carb rebuild tutorial. Chances are good that you can find the problem in one of those two reference links.

[RastaraL39]

Yes having scoured these pages I have read the newbie mistake page and of course have followed it's advice new petcock and so on. I was maybe trying to get a more specific answer.

[old_skool]

Sounds like blocked passages, probably need dipped longer, make sure you completely disassemble them, even from each other, use berrymans chem dip, its cheap and effective, follow that with a good rinse, and blow all passages with carb cleaner, I use a good set of carb brushes and either a bread twisty wire or small guitar string for all the tiny holes, leave nothing unchecked, and check everything at least 3 times, its easy to forget something or just not get it clean enough the first time. Make sure you mixture screw tips aren't broken off in the carb bodies as well, seems to be a newbie common mistake lately, these have very soft mixture screw springs which as long as your thread passages are clean, screw down easily, so lightly seat them, back out 2-1/2 turns. But your going to need to tear them apart again first, be careful removing your new o-rings not to damage them.
Rich

Oh, and it would be nice for an introduction and place your bike in your signature for future refference.

[old_skool]

Welcome

Here's your BassCliff welcome(currently on vacation)

You'll want to go through the maintenance lists in your "mega-welcome". You have a 30 year old motorcycle that probably needs 20 years worth of maintenance. Take NO shortcuts so that you and your bike will be insanely happy.

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.

Thank you for your indulgence,

Not BassCliff...lol
Rich

[Nessism]

If there is no fuel in #3 then you (obviously) have a fuel flow problem. Either the float needle is stuck closed or there is an obstruction somewhere. Honestly, this is pretty obvious yes? Time to go back though the carbs and make sure they are properly clean.

Did you fully break down the carbs and soak each one? Did you replace all the O-rings, including those on the intake pipe boots? Where are the pilot screws set? How many turns open?

And yes, float height is critical. You checked each carb right? If you perform the fuel height check as outlined in the carb rebuild tutorial you won't be guessing as to if the fuel height is correct and the float needle is working properly.

[btbarb]

What they said and POKE!

As a carb noob myself, I under estimated the need to poke all the jets and tubes even after dipping very well. I did poke and look, but apparently not good enough. I had to take the set on-off several times before i got every carb perfect. You should be able to flow gas into the set on the bench and figure out if something is blocking the fuel getting into #3.

We need to know what year the bike is to know what type carb you're working with.

[RastaraL39]

Thx for the replies, I did dip all the carbs for 24 hrs. will redip. Blew out all passages with comp. air and stuck a thin wire through them. Fully disassembled carbs per this site's carb overhaul instructions and replaced with cycle o-ring kit. Just a little frustrating I guess. Thx again.

[old_skool]

Here's another carb tip, I did everything as per the tutorial, but almost made a mistake others may have made and overlooked, so I'll share this almost goof on my part. After everything was spot on clean, checked, double checked, triple checked and was sure all was clean, I almost caused my own headache, at the final stage of reassembly, I was installing the float bowls, all proud of my SS hardware and all, but notice a little left over gasket material still where the bowl seats, so I decided to lightly sand that off, and just blow in there to remove any dust(the bowls-not the carb bodies)....then I thought just for the heck of it, I'd blow directly in the passage of the float bowl(had already done this earlier with carb cleaner and compressed air) and low and behold, something felt like a restriction compared to others, got a flashlight and shined down inside the bowl passage, and packed with sandings from my gasket cleaning. Had to re-poke in there and blow it out properly. So even when we have everything correct, its easy to miss or actually create a problem without thinking. Fortunately, I caught my mistake, but could see how this could have easily gone unnoticed had I not checked after myself a fourth time. Not saying this is your problem, but wanted to share a possible oversight.

[nejeff]

Thx for the replies, I did dip all the carbs for 24 hrs. will redip. Blew out all passages with comp. air and stuck a thin wire through them. Fully disassembled carbs per this site's carb overhaul instructions and replaced with cycle o-ring kit. Just a little frustrating I guess. Thx again.

I share your frustration! Been working on my carbs since June last year and they are still not right. Took my carb bank out yesterday for the fourth time. Hang with it...you are not alone

[RastaraL39]

thanks everyone.I took the carbs apart again and ultrasonically cleaned them in carb cleaner, reset the float heights, re-inspected everything and bench synched them. My new exhaust gaskets are arriving from Z1 today so I will be hanging the exhaust and starting it back up. it ran before with another carb bank off my other 850 so I know carbs are/were problem and I anticipate they won't be any longer. I'll let you all know how it turns out.

[RastaraL39]

Thank you posters/repliers. Good news. I hung the exhaust with the new gaskets and gave choke and hit the start button and VOILA! she started right up. So for the first few minutes it ran sorta OK but #2 cylinder not firing-exhaust pipe warm- able to keep my hand on it while running but not hot, had fuel in the bowl and spark- a bluish yellow spark. I recently purchased some ign. coils off an 850 that had 8500 miles on the clock and decided to swap the coil for #2,3 cylinders. I also tapped on the #2 carb bowl lightly with a wooden dowel and soft mallet while running. I restarted it and after a few minutes it settled into a nice stable 1300rpm idle and the #2 cyl. started firing! I could no longer keep my hand on it, it was hot like the others. No backfiring, popping etc. Will make sure everything is tight and safe to ride 'cause it will be another 80 degree day here. Maybe it was the subsequent dunking/ultrasonic cleaning of the carbs etc. Moral is be super thorough and don't give up [carbs] even though frustration is haunting you. Thx for the good info and advice.

[old_skool]

Glad it worked out, you mentioned still having to tap on the bowl, thought I'd ad this even though its probably been mentioned somewhere before, whenever you rebuild your carbs, when you source out new bowl gaskets if yours aren't reusable, be mindful that some of the aftermarket ones aren't properly trimmed and can cause your floats to get hung up, also, aftermarket floats sometimes come in tweaked, when measuring float height, don't just measure one side, measure both floats, you may have to bend them from left to right to get them even with each other, and carefully view their travel up and down for any such hanging, and make sure your float pin is free of burrs as it travels up and down smoothly. Just an added tip.

[RastaraL39]

update. many thx again-rode the bike 75 miles highway/city. Runs the way it should, plenty of power, just need to tweak the low speed air/fuel mix circuit as it seems a tad lean and sync carbs for final tune but perfectly rideable. good stable idle- no air leaks. Would have chased this problem around a lot longer I'm sure were it not for help from this site.