Spark plug, ignition strange one.

[Gazbrown]

OK brains out there. My 2000 ST1100 is doing weird things. 1.Hard to start. 2. Runs a bit rough. 3. Running rich.
Has brand new plugs, battery is good. Once running, I can pull the plug cap off the left hand side rear cylinder, and it runs better if it is not in direct contact with the plug! I swapped the plug cap, and it made no difference? The bike has not been sitting or neglected, up to this point has been running fine. Also, the choke doesn't seem to do anything except stop it running...stalls. Any ideas.

[Brock]

May be a bad coil pack..
Carby sync may be required.

[Gazbrown]

Thanks for that, a set of gauges is on order, so that's my next step...

[Jdbiker]

. Also, the choke doesn't seem to do anything except stop it running...stalls. Any ideas.



I know this may be simplistic, but which way are you pushing the choke lever , up or down? Because some owners manuals say choke is On in Up position, whereas Up is Off, and Down is On. If engine is cutting out when  you push the lever up it might be a fuel issue.

[hobs]

Hi Gaz, Had similar problem some time ago just after I had got my 1998 ST1100 back on the road. Was running rough, could pull a spark plug lead off and it made little difference. Problem was the rubber connections between the carbys and the intake had gone hard and were letting in air. Didn't realise how bad they had stiffened until I compaired them with a new set. I though they were still ok during the rebuild and didn't replace them until the bad running.
Cheers,
Hobs