No gas in #2 cylinder-1980 gs550e

[JS80550E]

I've been riding around for the past 2 weeks, and occassionally I'd get a misfire, however it has been gradually getting worse to the point that I can tell that I'm not running on all 4 cylinders. Last week when it was occasionally misfiring, I figured maybe bad plug, or some crud in the carbs. Replaced plugs. Still ran the same.

Now, as of about 3 days ago, the bike is only running on 3 cylinders. The #2 (second from the leftmost cylinder) is not firing at all. While bike is running, you can hold the header and not even feel it getting hot. Checked for spark-had strong spark. Actually ran the bike at idle without the spark plug in, and the air pumping out of the spark plug hole did not even smell of gas (also the plug was not wet when taken out).

The other day I took the carbs off and completely cleaned them (although they were pretty clean to begin with). Put them back on and still have no sort of firing in #2.

I had checked the cam to see if maybe somehow the intake cam foot for #2 wore down, not letting the valve to be pushed down far enough. Checked about 30 minutes ago. It was fine.

I am out of guessing, except for maybe the valves need to be done? Any suggestions would be great. I need to be mobile again asap.

[Nessism]

I suggest going though the bike and bringing all the maintenance items up to date. For example: full carb teardown, clean out, and reassembly with fresh O-rings (new O-rings on the intake boot pipes too), valve adjustment, clean or replace the air filter, replace/clean the spark plugs, check the petcock, etc. Most likely the problem you are having will clear up once you are done, and if not, at least you will know what the problem is not.

Please check my signature for the Newbie Mistakes thread and Carb Rebuild Tutorial.

Good luck and hope this helps.

[tom203]

I know you said plug #2 didn't appear wet, but since carb #2 has vacuum port for petcock, be suspicious, as this causes lots of problems. I'd plug off this port at carb nipple, put petcock lever on "prime" spot ( I hope you have this kind) and go for a spin to see if #2 header now gets hot. At least we could then rule out the petcock vac line.