2005 S4R thermostat question

[DucHead]

Gee-whiz - it's been a while since I posted.  I'm still riding my Monster and a bevy of Suzukis. 

I read through a few thermostat threads on the board, but didn't see exactly what I was searching for... dMy Monster coolant temp gets quite high (up to 200°F while riding), and I thought perhaps the thermostat shit the bed. So I drained the coolant and removed the thermostat and it opens at ~165°F. I cycled it a few times and it seems to be working although the opening temp seems a little high. I'm going to flush the system with 1:1 vinegar:DI water once the new silicone hose kit arrives and I re-assemble everything.

I believe that the two sensors that connect to the unions are to trigger the radiator fans, so I don't think that could be a problem.

Any thoughts?

[Duck-Stew]

IIRC, one is the fan switch (on/off through a relay) and the other sends the temp (variable voltage signal) to the ecu.

[ducpainter]

I might not have a ton of relevant information to add, but my track bike, that has no fan, runs at 180 while moving. No clue about the thermostat condition.

[DucHead]

Thanks, gents!

[koko64]

It's worth investigating thermostats for both coolant and relays for fan operation that cut in earlier. I've had to do this with both Triumphs and MV Agustas that don't like our climate down under. In the case of MVs bikeboy altered the ECUs fan programme to engage earlier and stay on longer. There are also high flow fan blades around the market. On both a 955 Daytona and F4, I have modified the coolant thermostat to work at a better flow rate. Too fast and the coolant doesn't loiter in the radiator long enough to exchange enough heat and too slow it doesn't keep up with motor speed and corresponding increases in heat. The ID of a coolant thermostat helps regulate flow so you would need to live in a very high temp climate to remove it altogether. There is a risk of the coolant moving through the heads too quickly as too high a flow rate may also not grab enough heat from the heads.

There are also manual fan switches available.

[greenmonster]

I have modified the coolant thermostat to work at a better flow rate.

Very interesting, how did you do that?