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Thermostat question

Discussion in 'Technical and Troubleshooting Torque' started by hornet, Sep 14, 2005.

  1. In any car I've driven, the temp gauge usually quickly pops up to the middle, or thereabouts, and stays there pretty much irrespective of outside circumstances. I understand that the thermostat stays closed to heat up the engine quickly, then opens to allow hot water to circulate quickly and keep the engine at an optimum temperature.
    But I've got no experience with bike thermostats (Hornet is my first non-air-cooled bike)
    If the day is cold, the temp gauge barely moves above the bottom marker, and never gets anywhere near the middle except on the hottest of days.
    Do bike thermostats behave differently, is mine faulty, or (as I suspect) has some dimwit removed it, and if so, how do I tell???
    End of ignorance display........

  2. Nah sounds the same as the VTR :)
  3. i've just been questioning the same thing with my bike too Paul. It never gets above the bottom marker. The only time it did was when it was a warm day and i was 'warming' the bike up. I started it and then went inside to get ready. I came back out maybe 5-10(at most) and it was near the middle. That's the closest it has ever come.

    It just seems that bike thermostats are either:

    A: much higher scale and therefore the bottom marker may be equivalent to the middle of a cars???


    B: They are just more efficient with dealing with the heat due to their design allowing the engine much better heat dispersal due to being so open. It may also be the fact that they are a much smaller capacity engine as comapred with cars??

  4. My VFR pretty much behaves like that too. My guess is that the motors don't get as hot anyway as Josh has suggested. They are exposed much more than a car engine is (though mine does move nearer the middle, remember it has a fairing)

    As the engines are alloy, that would tend to dissipate the heat quicker too.

    As long as the bike is not OVER-heating, I'd not worry about it.
  5. What does the digital readout say?
    Mine averages between 78 &82cel. in average weather, in hot weather the fans cut in @104 cel.
  6. tain't a digital readout, scooter, it's a 98 model so an old fashioned needle-type gauge......
  7. What is to stop you from removing the lid and checking the temp with a thermometer?
    That would be the place to start, otherwise pull out the thermostat and stick it in a saucepan on the stove and take note of when it opens.
    Maybe the guage is not particuarly accurate and you have nothing to worry about, probably the most likely scenario.
  8. thanks for that, I might get my mechanic to get HIS hands dirty and check, it's due for a service soon!!! I'll let you know what he finds!
  9. I personally think they should behave the same

    i.e. top radiator hose should stay cool until the bike gets up to normal operating temperature

    I'll let you know the answer when I pull mine out in a few days (my bike is doing the same thing)
  10. I'm not so much concerned about the bike warming up quickly enough, cos it seems to do that, but it seems to run so cold, at least that's what the gauge says. That said, other people are saying the same, so maybe I'm just imagining it!
  11. Keep in mind too that on a naked bike like the Hornet the engine is still going to get quite an effective amount of air-cooling.
  12. hmmmmm, hadn't accounted for the wind-chill factor, jd, I think you might be right. Thanks for your help peoples, just trying to be careful.......
  13. but will a bike thermostat ever be fully closed?

    if so, the top radiator hose should stay cool until the thermostat opens.. so should check that