not running in left cylinder

[mk2gti]

hey there, i got an old gs 425, bike has sat for 6 months, had varnish in carbs, cleaned it all up completely. bike is not putting gas in the left cylinder, carbs are getting gas into bottom of bowls. when bike is running it will smoke out the right exhaust only and not the left. when i put my hand over the left carb(not working cyl) to choke it it seems to pull gas in then and smoke goes out both mufflers. when i rev it it pops and backfires out the left cylinder (not working cyl) and will shoot a flame out the exhaust. bike wont idle. any helps is appriciatted

[mike_of_bbg]

When you say, "cleaned it up completely", does that mean you totally disassembled all parts of the carbs and soaked the metal bits at least overnight (better 24 hours) in carb dip? If the answer is no, you're likely to get a whole lot of people telling you to do so. Including me.

[mk2gti]

i didnt have them soaking in a bowl of cleaner but i covered them in a can of spray carb cleaner and let them soak in that for a few hours,

[mike10]

Yes soak them

There is a site on here that shows you in detail how to clean those carb's right. And even get new O- rings for them. Try Basscliff's site many questions will be ansewered . If those are CV carbs they will never work without the air box and filter. No air leaks, they are very picky.

[mk2gti]

alright ill check the website out. tomorrow im going to try cleaning and soaking them one more time, it seems like its getting gas in that cylinder to make it backfire and pop but not enough to run correctly.

[mike10]

A Gallon can

Get a gallon can of carb. cleaner at Auto parts store. It comes with a basket inside to put the parts in to submurge. Do not put in rubber or plastic parts. Just take both carbs, apart and follow cleaning directions. Per web site. It will most likely save headaches down the road. Plus you will know whats up with them. I would say don't mix the parts. do each separately. There are guys smarter than me here to help you. Do not be afraid they have never told me wrong.

[BassCliff]

Greetings and Salutations!!

Hi Mr. mk2gti,

Properly cleaned carbs, properly maintained air filter and sealed air intake system are just a few of the vital components necessary for happiness on a neglected GS. Let me cordially welcome you and toss a ton of information at you. It's how I say "Howdy!" ....

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

[mk2gti]

tight intake valve is on the list of ideas now, dont really expect it to be it since when i choke the carb on the non working site with my hand i feel air getting sucked in. im going to clean the carbs again. bass cliff, i was on your site and all your links were not working.

[chuck hahn]

What bike? Year? Original coils and wires? Just went thru this last night Was a bad resistor in the wire. Pull off the wire and look down inside the boot to see if theres a brass looking thingy with a screwdriver slot in it.. If so thats a resistor wire.. Remove that brass plug thingy and carefully dump the contents into your hand the porcellan thing is the offending resistor. Switch it with one in a working cylinder and see if that reverese the problem....if so get yourself some spare resistors and keep a few onhand. And you will notice that there are two different lenght wires also. the long stemmed ones go to the two inboard cylinders and the short go to the two outboard cylinders. The two LONG stems have a spring that holds the resistor in contact with the top of the plug when it is on the plug itself..the short stemmed ones do not require this spring. when you reassemble the boot put the spring in first ( IF REQUIRED ) then the resistor, then screw the plug thing back in...

[mk2gti]

its a gs425, 79. its a twin. i dont think it would be a bad resister in the wire, if i turn the bike over with no wire on the plug the plug is still dry, no gas. thanks alot tho for your input

[chuck hahn]

didnt know it was a twin...my bikes are all inline 4s.. but hey what the heck maybe someone will read my experience and benefit.. thats what its all about..I just went on bikebandit to SEE what the coils and wires looked like.Un fortunately the schematic didnt show the boots and if there were resistors or not.. seems i am learning a lot tonoght about tire codes and twins,,LOL

[mk2gti]

cleaned the carbs again, let them soak over night, i am certain that it is clean. i wanted to check if there was suction. i put my hand over the carb to choke it and it seems to pull gas through and makes the exhaust smoke like the other one thats working. put it seems like there is less suction in that carb then the carb on the working side. tight intake valve? any suggestions?

[Einstein]

When you put your hand over the carb, it fires, so forget the ignition.. it's working.
also, as it sucks fuel in when "choking" the valves arn't the problem either.

It is going to be a blockage in the jets, but could also be a leaking diapragm..


John

[mk2gti]

leaking diaphram, top part to the carbs? any way to check if they are bad? i just thought that since it will pull gas through when you choke it by hand then there was no blockages. thanks

[Einstein]

Lift the piston (in carb) with a finger, it should have some resistance, and also go down again smoothly, but gradual, not slam down.

There are a few jets in the carbs, but basically theres an idle jet for when it's... well, Idling !!
A main jet, from anywhere above idle.. and a needle jet, varies by the piston, and vacuum from the engine. You need to check these, and carefully clean them out with a bristle from a nylon brush, as it is less likely to damage them.

You never actually said whether it fires if you rev the engine up... it may just be the pilot jet (idle jet) that is blocked..

I doubt the float is bad, as that usually floods the carb... but the float height could be wrong..



John