little bit of misfiring between 1500 and 3000 rpm

[wicki]

Hi all,

my 12/1983er does some kind of misfiring at low speed and low rpm.
I cannot describe in other words: It feels, like one cylinder does not fire
randomly.

The engine starts up fine - even when its cold (with choke). When I put
the choke back slowly, the engine runs fine at about 800 rpm.
When I turn the throttle, it is a little tough, but it sounds good.

When driving, it is jerky. Getting better the warmer the engine is.
But the stuttering at up to 2500 rpm never stops completely.
Above 2500/3000 rpm it runs fine....

I checked the compression: on each cylinder about 11.5
I checked the spark plugs: they seem to bee new / in good condition
I checked the wires: they seem to be new / in good condition

I have not checked for creeping sparks in a dark garage with removed false tank yet.
(cause the misfiring only happens under load)

I tested a bottle of "carburetor cleaner" (liqui moly) in the tank and immediately the misfiring
was gone. (not completely - but 90% less)

Because of the "carburetor cleaner"-result, I thin, it may be a carburetor-problem.
But what kind of and how to solve it?

Any hints for me?

regards

wicki_w

[SIR tricky]

I use a shot of seafoam in the tank regularly that seems to help.

If you don't know when the plugs were changed even if they LOOK new, I used to change mine every year.

[wicki]

I use a shot of seafoam in the tank regularly that seems to help.

If you don't know when the plugs were changed even if they LOOK new, I used to change mine every year.

status now:
I changed the complete carburetor to the one of my other gl1200.
now the engine runs fine.
then I cleaned the carburetor manually (swimmer-chambers, nozzles)
and installed it back into my other gl1200.
it also runs fine then.

so, the reason was the carburetor....