On days when the temperature reaches above 90 my 2006 Heritage runs poorly, almost feels like it has a miss. When the weather is cooler the bike runs great. Just had the 1,000 mile service done and the dealer told me that this is normal. Bike is all stock. Is this normal? Would any mods help? Thanks.

 

my 05 fatboy runs better on cooler days, but i dont think it misses, possibly you need some kind of fuel mixture adjustment.maybe a high flow air filter.. is it carb or fuel injected... kerry

 

It's fuel injected.

 

yes this is very normal of any motorcycle.....you will get optimum performance out of ur bike on the cooler days, especially on like a 65 degree day

 

It may be the Heat Management System on the bike. HD has a program in place on the injected bikes that shuts down a cylinder or creates a miss to richhen the engine and cool it in a overheat condition.

I had it happen once in bad traffic on a 105 degree day, engine temp reached over 300 degrees, it is a general loss of power with a slight miss at idle.

I live in the dessert area of Ca and it is always over 90 in the summer, I have never had it happen on normal rides. If you are overheating on normal rides in 90 - 110 degree temps there is something wrong with your bike. It may be to lean, check your engine temp and get the bike on either a dyno with a exhaust analizer or a least a exhaust anailizer to check the mixture.

 

All bikes run better in cooler weather, at least of of the number of bikes I have owned.

 

My Street Bob would vibrate like a cheap hotel bed in any temp under 60. When It warmed up the Vibs would lessen considerably.The FXSTC runs smooth in all temps so far. I had it out yesterday in 94 degree/80 % Humidity and was smooth as silk no problems at all.Then again , I never sat still for more than a few mins waiting on lights to change.

 

On hot days, especially when the humidity is high, engines will loose some power, but yours sounds a bit extreme. Back when I had an airplane, I had to lean out the mixture a bit on hot days to get it to run right. The newer fuel injection systems should be able to do that on their own, so you might want to get the dealer to run a check on the injection syste, to see if a sensor is going out.

 

Try running a higher octane gas when it get's warmer also... 100 if you can get it.