RF 900 Running Temperature

[dailyk]

Hello. I just bought a 1994 RF900, and I am new to the forum. I have a question about the temperature at idle. It runs fine when moving. When in traffic., The temp needle goes 3/4 the way up at its farthest. The fan works fine, and it does not hit the red zone, it just gets pretty darn close (less than 1/8 away). I just want to make sure that it is OK to go up that far, and that everything (pump, radiator, etc.) are all OK. I have not seen any other info that clues me in. Thanks

[onearmedbandit]

My bike has temp readout, in usual riding circumstance she sits at about 72-80 deg, but in traffic will go up to 106 before the fan kicks in. It's normal apparently.

[MacD]

There have been a number of threads about RFs and their thermostats, usually they run too cold while moving.

What your RF is doing sounds very similar to what mine did, run cold when moving (about 1/3 of the way up) and heat up in traffic (say 3/4 of the way up) particularly in summer. As long as the fan comes on and the temperature stops climbing I'd say everything is OK. The pressure cap for the cooling system is located under the RHS black panel on the fairing. You should be able to see flow when the engine is running even when cold as the thermostat has around 5 holes drilled in the surround.

Unless you know the coolant has been changed recently it's always a good idea to change it when you get a bike. The "antifreeze" loses it's anti-corrosion properties with time. Use a 50:50 mixture.

[Lou Girardin]

Mine did the same.

[Lil_Byte]

My RF400 was the same - used to worry the shit out of me until I found out it was normal

[Chookah]

My RF is pretty much the same, but not anything to worry about I shouldn't think.
Probably an artifact of slightly older technology that relies on a thermostat switch to switch the fan on and off rather than a computer monitoring the temperature.

[Chookah]

I have posted this elsewhere in another thread but I will repeat it here also

Further comment on the thermostats.
The suzuki factory sevice manual for an RF900 (94 to 98) says that the thermostat should open between 75 - 79 degress and the fan should on/off at 105/100.

By comparison a Hayabusa (again from a factory manual) has 82 degrees for the thermostat and 105/100 for the fan.

Both seem quite low to me, but the RF especially so.