After riding several summers through 100+* gridlock Denver metro Iíve only had to stop twice. Well actually once. The temp gauge blinked the first time and I stopped right there. The second time this past summer I stopped because it got too hot on the legs although the temp gauge was fine. Iím talking 4 lanes, five if you including the on/ off ramps of standstill super soaked heat.
What I did differently after the first incident was add a secondary fan switch and use specific coolant. 50/50 coolant fall, winter, and spring. Water/ water wetter for the hot summer months. Using a infrared laser thermometer just prior and immediately after switching to the summer mix aimed right at the stator cover yielded 5-10* difference cooler operating temp.
My bike has one fan and over 20,000 miles between the first and second incident where I pulled over. I ride a ZX12R.
Alternatively to these suggestions and the idea of adding a second fan is using a controller that allows you to lower the fans on/off settings. I have not personally used these products but you can find them on ebay. From the items description it does the same thing as adding a secondary fan switch but instead of a manual operation is operates automatically like oem at the temp setting you select.
Another option is switching to a quality synthetic oil where Iíve also observed another 5-10* cooler operating temp.
The two main constants throughout those 20k+ miles between the first and second incident: The use of a secondary fan switch (about $3-4) and using the right mix of coolant. I just switched from summer mix back to 50/50 now the ambient temps are going down and happy as can be.
Iím suggesting these ideas because your system was designed to operate on one fan, not two. As you mention, these charging systems do not have a lot of surplus.
This past winter I added heated gear. Jacket and gloves. Did the math. Added up the power requirements, subtract that from the charging systems output and it was close. Too close. Adding a second fan may not be an immediate issue but it will limit additional electronics you might want to add in the future. My bike is loaded with electronics. A second fan would very likely kill my bikes charging system very quickly.
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