Rough running

[Melena]

This spring I had the BMW shop do a complete 10,000 mile service on the bike.  They don't usually do the Airheads, but I had a very large gift certificate from them that I got for my 15 year anniversary at work.  So, the owner (Dennis) said he would do the job as no one else in the shop knows how to work on them.  He did the service, and my friend was able to get the bike home for me as my right foot was in a cast for 7 weeks after foot surgery and I couldn't ride until I could get my boot on.  So the bike sat through the summer until just a couple of weeks ago when I could finally ride again.  Okay, so that sets the stage.

Now that I've had a chance to ride on a fairly long fast ride, and several days of a short commute, I've been able to notice a few things.  At first I thought the bike felt like it was surging - like power surges.  But I couldn't tell if it was the bike or me just getting used to the bike again.  It still seems like it does surge a bit, but it seems to be running rough.  

Maybe the timing is a bit off?  Oh, and I did notice another thing.  I have new pipes too.  I've been watching the change in the color by the heads.  The left side has turned more purple than the right side.  Does this show that one side is  hotter than the other side?  

The idle is at around 500 rpm.  Isn't the idle supposed to be around 900 - 1000 rpm?  When I get to a stop sign it tends to die, especially if I've been up to speed and have to stop fast.  But I also have to keep the throttle up so it doesn't die at any stop sign even when going slow.  

I'm thinking that the valves should be checked and the timing adjusted, and the idle should be set higher.

The clutch is set out more too.  It doesn't seem to catch  until right at the end.  Shouldn't I have a bit more play in it?  Maybe this is the way it's supposd to be?

Any thoughts on how I can make it run smoother?

Thanks!

[scuba]

Maybe its just a matter of fuel level in carburetter/s. In some point it gets dry on "colder side" and therefore the engine runs with less power until fuel riches the bowl. Check carb balance. Check air filter and those greasy, dirty pipes under it which are ventilating engine and oil vapours (again my bad english). Did you smell distinctive odour of clutch plate? If you didn't maybe the cluch plate is ok and you need to adjust it according to your preferences. And adjust idle rpms to 800. This slow idle can cause bad lubricating when engine runs longer time at idle speed. But slow idle doesn't cause lack of power when riding.

as would trolle said, greetings from cloudy sutheast Europe at 9 deg. centigrade with slow rain  

[k_enn]

Also, with the bike sitting unused for almost 2 month, the gasoline may have gone a little stale, and you may have some build up in the fuel system.  The first thing I would do (after adjusting the idle higher) is to run the tank down to reserve, fill up, and put in some carborator cleaner.

k_enn

[MrRiden]

Melena,
Surging / rough running / stalling / uneven discoloration of pipes / way low idle all point to the carbs. They need to be checked for crud in the fuel lines tank screen & float bowl / leaking diaphragm / float level / blockage of idle circuit / air leaks / properly sealing float bowl gasket / and finally blanace. First tho, the valve adjustment and timing need to be verified.
Clutch cable should yield some slack at the lever. give the cable sheath a yank and let us know if you have a bit of a gap between the cable sheath and the point where it meets up with the lever housing.
rich

[nhmaf]

Around here, I'd also suggest that you take off the air cleaner and check that it hasn't become a honeymoon hide-away and food storage unit for some little rodent(s)...
Any vehicle in my area that sits for more than a few weeks without running is prone to get some "squatters"...

[Melena]

Thanks!  All great advice.  I'll check it all out.

The gas was a bit old, but it was really low too, and I did fill up at the beginning of my first ride.  It's time to fill up again.  

I did forget to mention one thing.  When the engine is decompressing (I think that's what you call it when the engine is slowing down from high revs) there are a series of small backfires.  POP, pop pop pop-pop-pop.  That's another thing that makes me think the timing is off a bit.

I doubt that there are any small rodent type creatures hiding away in the air cleaner as there are so many cats around here.      But I'll check it out anyway.  You never know.  

[steve hawkins]

That means you probably have an air leak as well at the exhaust, close to the heads.  Looks like your new pipes need snugging up a bit.

Watch those header nuts when you are doing it.

Steve H

[trolle]

And while you're at it, check that the fuel lines are tight - old lines will fray at the ends and let false air in.

Backfiring is normally a symptom of  too rich a mixture, so I would check the airscrew at the bottom of the carb: turn it clockwise till it reaches bottom and then counter clockwise  appr. 3/4 turn or until the engine reaches the highest rev. The last bit is of course done on a warm, idling engine.

Hope your shoulder and feet are allright and that you will have a few nice rides in the fall.

greetings from a sunny north, cool with good riding conditions