Coming into this time of year, we get a lot of phone calls regarding engine temperature and oil pressure. Customers have concerns that their bikes are running hot, while others state that oil pressure seems to go down at an idle when hot. Although several variables come into play, the two we have to keep in mind, are oil selection, and the fact that all Harleys (with exception to the V-ROD) are AIR COOLED motors.

Oil is a contributing factor to the motors cooling capabilities. For convenience, we tend to run multi-viscosity oil. Meaning it works in both cool and WARM temperatures. If you refer to your owner’s manual, it shows oil specifications recommended for different temperatures. For instance, SAE 50 would be used when temperatures are above 60 degrees, and SAE 60 for temperatures above 80 degrees. The drawback to “straight” oil, is that ‘cold starting’ below 50 degrees is sacrificed. So, on 100 degree days, when the bike has been sitting in traffic for 30 minutes and our oil pressure is reading low, we can isolate the break down point of the oil, and the lack of air flowing through the motor as the most probable cause! The best solutions are to run heavier oil, and try at best to avoid “parade” style riding. A representative from the factory presented me with a valid point last year. Riders don’t want to take their bike out when its 30 degrees. “That’s too cold!”, he said, “…but nobody ever thinks it’s too hot!”