When an Engine Gets Hot

[Bikergeek]

Just a thought here , I really don't know how accurate those oil tank thermometers are really . Yesterday it was 80 here , I got stuck at a light where I had to wait for it to change twice before I could make it through . I could really feel the heat from the exhaut on my leg . When I got home I decided to put my rochester thermometer in the oil to check the temp. , it said 180 , and this was only about 1 1/2 miles from the light to my house at 40 mph . I do run synthetic but the exhaust makes it seem hotter than it really is IMO .

I just did the oil tank thermometer test by putting my oil tank thermometer in water and watched the temp. It was very accurate within 1-3 degrees. Water started to boil with a reading of approx. 214 degrees based on my subjective view of the temp gauge. Not bad!!


I also checked with my local H-D dealer service guy and he told me the EITMS is available on my '08 Heritage Softail at a cost of around $200.00. He actually told me many Harley owners here aren't happy with it. Some ask to have it turned off. He told me, "Don't bother with it."

 

[R_W_B]

Correct me if I'm wrong, but I thought I read somewhere that the motor needs to be idling at least 900 rpm for the oil pump to function properly. Seems if the oil pump isn't putting out enough pressure, the motor is gonna run hotter at low idle speeds. Maybe this is different in the newer bikes with the EITMS.

Don't know, that might be true. The 850 rpm was from my tach reading which could have a few hundred rpm ambiguous display. Here is the official HD quote:

Once the ECU determines the engine is warmed up, it goes into closed loop mode and will idle at a very lean (and rather warm) 14.6:1. Normal idle speed is 1050. It must be noted that technically an 14.6:1 AFR is not lean, but it is not an ideal fuel mixture for an air cooled motorcycle engine.

In high temp mode the engine RPMs drops to 950 and the ECU goes to open loop mode, richening the fuel mixture to 12.0:1 in an attempt to cool the engine. As soon as the engine RPMs hits 1200, the ECU goes back to closed loop mode at 14.6:1