Well, that time of year I guess. Now that I have my bike running right after front head gasket replacement and valve adjustment, I let her idle for awhile in the garage. I came back 10 minutes later to find steam and antifreeze coming out the overflow tube at the bottom.
Figuring it was a thermostat, I pulled the thermostat off, and ordered a new thermostat and radiator cap. With the nice weather today, I took the bike to work and after getting stuck in some traffic, the temp got really hot again and I had to pull over and let her cool awhile. When I did, I noticed some antifreeze loss again, but also felt the contents of the pipe from the radiator to the thermostat housing was boiling.
Any other thoughts besides radiator cap?
Thanks
Nick
Nick... Continuous engine temps above 220ºF or 104ºC is a problem and the logical order of items to trouble shoot are:
1)Faulty radiator cap... system should hold 1.1 pressure ratio... 2)Insufficient coolant... 3)Passages blocked in the radiator, hose or water jacket... 4)Air in the system... 5)Thermostat stuck closed... 6)Faulty temp meter or thermo sensor... 7)Faulty fan... 8)Faulty fan switch...
Engine temps below 180ºF or 82ºC is an problem... it means that the moisture produced during combustion is not getting hot enough to evaporate out the pipe as steam... instead that moisture will migrate to the oil and produce a milky white contamination...
Note normal by products of combustion is water... . Every gallon of gas creates roughly 8 pounds of water vapor... we all have witnessed water escaping out of tail pipes on cold mornings...
Thanks. Come to think of it, the radiator fans did not come on so this morning I tested the wires. I put a jumper wire on the two female sockets of the fan switch and the fans cycled on so the wiring is good. I'll order a new switch.
I used to get all sorts of corrosion/crap in the t-stat plug on the bottom rad, where the thermal switch for the fans is.. usually people just end up by-passing that and adding a hard switch in there so they can control the fans as needed.
New thermostat, radiator cap, and a bleed improved things but she was still running hot on the stand. I picked up a new thermal switch at NAPA Part # FS 130 made by Eichlin and it was a direct fit. An internet poster said that it had a lower temperature trigger. I tested today and the fans came on when the temp was about 1/3 - 1/2 way on the gauge. I'm very pleased.
Was having the same issues. Fan switch turned out to be the issue. New thermostat and Rad cap while it was sitting and flushed the radiator. Next up is a manual switch to keep it below temps while splitting lanes (which is, by the way, totally legal here in So Cal...LOL).
End of thread · 6 posts recoveredWayback Machine snapshot 6 Jul 2017