Friday, August 07, 2009
The Cooling System
With the rally over, I now had time to have the cooling system checked to see if there was some reason the bike heated up faster than other Wings I rode with. A rad blockage, a kinked coolant hose or possibly an incompletely opening thermostat.
The real cause is a poorly designed fan system. For those not familiar with GoldWings, they have two radiators oriented sideways, one on each side. The traditional transverse radiator has a fan behind it that sucks more air through at low speeds promoting better heat exchange. In GL1500 focus groups, some mentioned disliking the hot air blowing back on their legs at stoplights. At this point, some Honda engineer screwed up big time.
Instead of considering that the for-and-aft rad wouldn't blow heat directly back on the rider, this wonderchild designed the fans to suck air in from the side and blow it out the FRONT. This is fine at a stop, but once you start moving, the air from the movement works against the fans and reduces the flow. Then, at 15 MPH, the fan shuts off to end the conflict. Unfortunately, on a hot day, it takes about 40 MPH to generate enough air flow to cool it back down to normal levels.
In extreme conditions, like climbing Chimney Rock Hill or Wolf Pen Gap at low speeds last month, the temperature gauge can get to the red and force you to stop. Sometimes on these roads there is no place to stop. It bothers me that all the hardware is in place and yet I can't be assured it will keep the bike in operating range.
Tuesday, I took the bike to R&L and they went over the entire system. The only change was the thermostat, which was located way down below the fuel tank and was replaced strictly as a preventative measure. No problems were found.
Sandy drove me down and I picked the bike up today. Ted & Helena, people we rode west with in 2000, were at the shop. We hadn't seen them for a while. Ray L. from the Freedom Riders was there, too and Ken S. arrived with Helen to pick up his ST1300 while we were there. Ken and I rode back to Sudbury together after I took a minute to reroute Sandy's electric vest cord. Derek never gets this right. I also needed to get gas because the last of the tank was obviously drained so it could be removed and realized on the road that the clutch lever setting had been changed and not set back again.
It looks like the bike doesn't run any cooler. The big fix is going to be to get after-market fans that are pitched to blow the other way. They drop right in, although they need new mounting holes drilled. It would have been nice just to reverse the wires on the DC fan motor but the pitch of the blades wouldn't be right. The last step is to run a hot wire to the fan to by-pass the 15 MPH shutoff and control it with a switch. Do this with the two huge rads and the beast will never overheat.
One thing that did cross my mind about running hotter than other Wings is that, at 50K Kms, I installed a K&N air filter. Despite the O2 sensors, the additional air flow might have leaned the bike out causing it to run hotter. Before I rip the fans apart, I may drop a stock air filter in there to see if it makes a difference.
The heating only happens rarely but it shouldn't happen at all. It's the last peeve I have with this machine and so, considering the time I spend aboard, it is worth it in my mind to get it fixed once and for all.