while we are in winter how long should the bike run if you start it

 

Don run the bike till you can ride it. Running it in the garage, it won get hot enough burn of the moisture that will collect in your oil. Not sure though, I think it takes abour 8 miles to get to oil warm enough to burn off the moisture that collects in your oil.

 

nicktown is very close to right on. just remember at 50 degree weather yes 8 to 10 miles, but at 30 degree you may want to go 15 to 18 miles.

 

I would say around 20 miles for any short ride in cold weather.

 

I will go along with grbrown, what do I know about cold weather I ride in Arizona. :-)

 

Usually till the motor is up to full operating temps....

 

When the tranny is hot to the touch you got it cooking enough.

 

short trips can be hard on the oil but one has to keep an eye for the tells. if no tells, probably doing fine and a few here and there will not hurt. my oil really never warms up to the point of boiling the water out even in the summer. do i have condensation issues, nope. most of the blow-by will be hot gas and a little water which most of it will vent. so a no.1 tell would be in the air cleaner.
now just to oil up an engine for a few seconds of run time probably won't hurt either since you are only talking about what 3 months of winter with maybe a good run in between. what does hurt is running on enrichment which contaminates the oil with fuel and can wash off cyl lube.