Cylinders 3 & 4 not running

[aaronerman]

History
My bike is a 1980 Suzuki GS 1100E, in GREAT cosmetic condition. I've owned it for a few years... haven't touched it in about one year until last week. It's time to get her running right again. She wasn't quite giving the performance she used to.
What I've Done
Valve job
Compression test (all up to 150psi on the dot)
All plugs firing
THE PROBLEM(S)
First noticed that water on my two left pipes (cylinders 1 & 2) was steaming off immediately when i sprayed it on. However the two right exhaust ( 3 & 4) the water just beads up and slowly evaporates. This led me to believe that my spark wasn't good. However I'm getting an awesome spark on all four cylinders. So I started her up again, and this time took the boots off of # 3 & 4 while running... absolutely no change to the way it ran. So I'm thinking that I'm not getting ANY fuel to the right cylinders, and my bike is only running on two! Any thoughts on this? What do I need to do next?
I've got the stock 4 BS34SS Mikuni carbs.

[tejasmud]

Yep, Classic.

From your description sounds like you just need to pull the carburetors and clean them. Actually dissasemble them completely, dip them minus the rubber parts, poke out all the tiny passages and jets, replace o-rings, ect..

Do that, and I would bet you will be getting fuel.

The idle circut of the carburetors and enrichining/choke system has a few tiny holes/jets about the size of a 'tip of a needle' in diameter. Over time with residual fuel left in the carburetors the fuel evaporates leaving behind varnish. The varnish is what clogs the tiny holes and passages, and in many cases carburetor dip is the only way to loosen it up.

Sometimes poking out the pilot jets and tiny holes in the choke system works if you know what you are looking for, but if it is unknown the last time the carburetors were rebuilt and are not keen it would warrant a complete overhaul in opinion.

Highly recomended that the carburetors be pulled, dipped, and new o-rings be used. After that, bench sync before putting them on, and then actually sync the carbs with the bike running.

Should eliminate issues with fuel delivery in the carbs. If not then it would be a question of the condition inside the fuel tank, or the petcock fuel valve if problems persist with the fuel.

Assuming it has new intake hardware and the air box is sealed.


E

[sparki]

although i agree with whats been written.... it's a lot of work. i'd pull the jets and clear them all first before doing the rest. jets is a few hours while full strip and clean and orings will take.... considerably.... longer. if it goes alright after clearing the jets the jobs a good un

[cowboyup3371]

Sorry Sparki but I would disagree. Pulling it fully apart and soaking everything will only take about a day for everything if you have the ability to do it all at once.

Take the time and do it right. Although I had mostly electrical problems keeping me from doing much, it was mostly because I soaked everything at first (with CdNoel's guidance). I've had it out doing 55mph (too nervous to go faster right now) and it ran good but not great. Consequently, I'm now doing my valve clearance job to get it that little extra bit.

[tejasmud]

It's not that bad of a job really. There is even a tutorial on BassCliff's website.

And, also to save some frustration if you very well venture the 'full rebuild' path make sure ANY jets or air/fuel screws you remove are removed with screwdrivers that fit the jets/screws tightly.

If really gunked up penetrating oil may help. Some even prescribe a little heat to help free the jets or air/fuel screws, which works also. Even if you have to buy 2 or 3 $1.50 screwdrivers and file them down to fit, it will sure beat having the urge to post, 'I have a stripped out pilot jet'.

Then there is more. Also to save the possible need to locate another carburetor body make sure the pins holding the floats are removed carfully. Support the posts with something so there will not be the urge to create a 'broken float post thread.'

Also, try doing a 'search' on some of the things mentioned to become a little more educated on the subjects, and you'll be fine.


E

[legaleli]

I'd check to make sure the plug wires on three and four aren't crossed first - you've got spark - but maybe at the wrong time...

[aaronerman]

All very useful, and thank you! Unfortunately I have to work a two day shift... but this weekend is GS time.

Should I just use over the counter carb cleaner? And I suppose this means buying a rebuild kit. Any preferred manufacturers?

[cowboyup3371]

Yea, berrymans is great and Walmart carries the smaller cans for $2 - just don't pour the excess into a plastic container for keeping, even for a minute or two...from experience

[850 Combat]

I'd check to make sure the plug wires on three and four aren't crossed first - you've got spark - but maybe at the wrong time...

Have you checked this?

1 and 4 fire together, 2 and 3 fire together. Its an easy fix.

As to the full dip vs jet cleaning, I hate to pull the carbs off the rack. I can R&R the carbs, clean the pilot circuit and jets and have it buttoned back up in about an hour, with a pretty high success rate.

[BassCliff]

Hi Mr. aaronerman,

Do not use the aftermarket carb rebuild kits. Instead, get an O-ring kit from Robert Barr ( http://cycleorings.com ), then completely disassemble, dip (for up to 24 hours), and reassemble the carbs with the new O-rings. There is a link to the procedure in your "mega-welcome" along with a TON of other maintenance tasks, tips, vendors, "how to" guides, etc. Let's get started.

Anyway, 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

[aaronerman]

Thanks~ I just ordered the o-ring set. I've got all 4 soaking after one hell of a time getting them apart. The philips screws were stripping, so I'm getting new hardware this time around.

[shibby_cbs]

not trying to hijack the thread but i am having a similar problem with a twist...my bike runs on cylanders 3 and 4 and not 1 and 2 and only after spraying starter fluid into the cylanders...it wont start on its own...good spark on all plugs...the twist is i dipped and cleaned my carbs no less than 2 months ago and the bike was running fine. i also did a valve job shortly after but had to pull the head and jugs off but was unable to redo the valve job when i reassembled it...now she wont run on 1 and 2