One maybe 2 cylinders not working

[Guest]

I have a '81 gs1000 that I just got. I can run the engine but it is rough and sluggish. The exhaust from number one is cold. 2,3 are hot and 4 is warm after 20-30 seconds of running. I have changed all spark plugs and have tested number 1 by pulling it out and seeing the spark. I don't think it's the ignition coil. It seems to me to be little to no fuel in 1. Any one have any better ideas on where to start narrowing my search for the problem.

[rwnielsen]

Do you have any history on the bike and... Factory air cleaner or pods?

[hillsy]

If you are certain it has spark, then you probably need to clean the carbs.

However, problems with 1 and 4 simultaneously ring a few alarm bells as they share the same coil.

[Trinnypig]

It does have pods on and does run a little rich. i just don't see why pods would make a difference to 2 cylinders and not all 4. i think i am going to pull the carbs out and clean them up and go from there unless you have any better ideas. Where can i get new coils if i choose to replace them?

[Nessism]

Please read the Newbie Mistakes thread linked in my signature. It will teach you a thing or two about GS's and what to do to avoid common missteps from those not familiar with maintaining a 33 year old motorcycle.

[Steve]

... i just don't see why pods would make a difference to 2 cylinders and not all 4. ...

You are right, pods have nothing to do with 2 cyl vs all 4, but since you have not given many details, we are forced to ask some of the usual questions. The use of pods will require different jetting than a stock airbox. While on-topic, ... you have stock exhaust or a header? Again, different jetting. You help us by telling us what you have, we can help you with better suggestions.

Since you have just gotten the bike, you really have no idea of its recent history. If it has been parked for a while, your cold cylinder issues could very easily be due to dirty carbs. Observing the presence/absence of spark on 1 and 4 will help confirm that.

Nessism suggested reading (and following) the "Top Newbie Mistakes" article that is linked in his thread. ALL of those items are important. Even if the previous owner claimed that something was done, VERIFY. You will also note in his signature a very good quote: "To measure is to know." "Measuring" does not necessarily mean that you need to know the size. It can also be interpreted as "observe and verify". If the owner claimed 'new tires', you can "measure" them by observing tread depth and date code.

You mentioned you are going to pull the carbs to clean them. Be prepared. It is not as simple as dropping the float bowls and spritzing some spray in there. Also in Nessism's signature, you will find the best how-to guide for cleaning your carbs. It is a detailed process that will span several days, as well as the purchase of some parts, supplies and tools. If you look over the guide and feel that you might not be up to the task, there are a few of us (including me ) that offer a carb rebuilding service for your convenience.

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[huntb]

Clean and sync your carbs

[wymple]

Easiest thing to do is swap coils with each other and see if the trouble transfers to the 2-3 cylinders. It won't cost a dime and will confirm or rule out a coil, which is a major suspect.

[glib]

The senior members on this site focus on the carb cleaning process for good reason. I have only been on here for a few months but found their advice to be exactly correct. Until you know that every orifice and passageway in your carbs is squeaky clean, you are just wasting your time looking at other causes.

[wymple]

And conversely, the best carbs aren't worth a damn if the fire ain't there. Start on either end. It's faster and cheaper to find out if it's firing right.

[Steve]

And conversely, the best carbs aren't worth a damn if the fire ain't there. Start on either end. It's faster and cheaper to find out if it's firing right.

Easily confirmed by pulling the spark plugs, re-connecting the wire and laying the plug on the head, then cranking the engine to see if there is spark. And, ... he said in the original post that he had already done that.

Definitely the quicker route, but he'll end up cleaning the carbs anyway.

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