Tindevil wrote:
Could this be a problem? I ride to and from work about 30 miles each way. I leave in the AM and the temp is about 55F. I come home in the afternoon and the temp is about 85F. My bike runs great in the morning but seems very sluggish at hi RPM's on way home. Is this possible with only mild temp changes? Traffic conditions is about the same both directions. Maybe it's all in my head. Maybe just anxious to get home for cocktail hour and bike just seems to run slower. Thanks, Jim
This is a very known, and noticeable, phenomenon in the variable climate I live in. And there is an explaination for it. Colder air are more compressed than warm air, and you get a much better filling of the cylinders. Secondly the colder air stream will cool down the engine more than hot air.
You should check the spark plug colour after a ride in hot weather. My guess is that since your bike is running better in cold mornings than on warm afternoons, it is running a bit rich.
But it's just an estimated guess. The only way to tell for shure is by reading the spark plugs.