Hesitation or dieing after start

[subforry]

Hi all,

Over the past 2 months my K1100RS has started to be more and more fussy after a cold start.  Now I have to use the throttle advance (choke) or it will die.  There is hesitation that seems like a fuel mixture problem.  This all goes away after about 5-10 minutes of riding.  I changed the fuel filter 2.5 years and 5k miles ago.  It was so bad on my last trip that I tried a bottle of Techron.  The hesitation is like a dirty carb that or poorly tuned carb that does not atomize the fuel until it warms up.   Once it is warmed up, it runs great.

Any thoughts?

[Scott_]

My 1st thought would be to check the water temp sensor. Both the connections, and the resistance reading of it.
I think there is a post in the Lieberry with a chart/listing of approximate resistance/temperature.
Another check would be to look for any vacuum leaks, old, cracked hoses, o-rings, the little caps on the balance ports, etc... then can/will give you grief.

[subforry]

How about this being unplugged?  Seems like an air temp sensor.  Just changed the oil and found it unplugged.  After I changed the oil and plugged the sensor back in it seemed to run better.  The u clip on the plug is missing, guess I need a green zip tie.

[Scott_]

Yes, that is the air temp sensor.
It would have an effect on the fuel enrichment, but I don't think that it would affect it as much as the water temp sensor though.

[The Mighty Gryphon]

Not to change the subject, but what is that insulation in the photo of the air temp sensor?  Looks like a fuzzy johnny blanket

[subforry]

Short ride to work and no problems.  Still when I get time I will check the water temp sensor.

The fuzzy Johnny blanket is the common heat and sound insulation you can get at auto parts stores.  It is felt mat about 1/4" thick with a reflective heat resistant material on one side.

[F14CRAZY]

How cold are we talking? Below maybe 40 degrees I have to use full "choke to start," which I can pull off to half after maybe 30 seconds, then i leave that on for a few minutes after taking off

[subforry]

How cold are we talking? Below maybe 40 degrees I have to use full "choke to start," which I can pull off to half after maybe 30 seconds, then i leave that on for a few minutes after taking off

What I said was not clear.  I meant cold as in when I first start it in the morning or after it has cooled.  Before I almost never use the choke because the air temp is usually 60F