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CBR250RR Fan Issue

Discussion in 'Technical and Troubleshooting Torque' started by TWOMEY, Jun 18, 2013.

  1. My cooling fan on my CBR250RR is not engaging after hitting the halfway mark, I am located in Kensington and I have only moved to Melbourne in the last 4 months so I am not sure who is good/isnt a rip off

    Is anyone on here an auto elec? or could recommend me somewhere to take my bike that isn't to far/close to public transport!

  2. #2 Unconnected, Jun 18, 2013
    Last edited: Jun 18, 2013
    This is a common situation it seems on 250RR's and other bikes with that engine as well as many other Hondas from the era.

    Generally it can be a few things:
    1. the bike is not getting hot enough to need to the fan

    On my hornet (which shares an engine with the 250RR) it would literally require the bike to be at max temperature before the fan kicked in, im pretty sure it only kicked in one or two times in the 10 months i owned it.

    This is because the engines can run very hot with out a problem and the rad is effective enough not to need much air passing over it, so the fan doesnt kick in until the coolant is nearly at boiling point pretty much. With such a small engine this doenst happen unless your sitting in traffic on a 40 degree day for more than 10 mins, that does happen, but sometimes you just need to filter, take a side road where you can average 40kph or so or 60kph at best or just pull over and let it cool down.

    2. The fan or thermostat doesn't work

    If like i suspect on my current VFR, the fan does not work (could be thermo fault as well) then its still quite a manageable situation, as with before, the bikes rarely need the fans anyway, so as long as you avoid huge traffic jams on 40 degree days then your fine, especially at this time of year at least.

    There are a few bodge solutions, wire up a powerful pc fan to the battery and connect it with a simple switch and use your brain as the thermostat, or im also pretty sure you can take apart the thermostat and clean everything as gunk can build up and stop it working, there are guides online.

    In this whether it definitely isnt a problem.
  3. check the fuses

    check the fan is plugged in

    check the fan works (wire it to a 12v power supply)

    check the thermostat (multimeter and a jug of boiling water)

    check/inspect electrical connections and earths (visual inspection for corrosion, check with multimeter)

    the above are all very basic DIY checks common faults that could save you a bit of money.
    • Agree Agree x 1