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Engine Heating Up

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by noobie_rider, Jun 2, 2006.

  1. Hey Guys,

    I've just noticed on the temp gauge of the CBR250 that the needle is almost reaching the red line. The place where I bought it said that is was normal for a CBR to get that hot ..... but i'm not so sure. What do guys think?
  2. Is this when you're in traffic or moving at a steady pace? Most bikes heat up a fair bit more in traffic, but should cool down quickly when moving again.

    Where do you live, could be normal if you're up the top end of the country.

    Flushing your radiator will get any crud out, and while you're at it check that the cooling fins on the radiator aren't blocked up.

    Use a garden hose gently from the back of the radiators to get rid of any build up between the fins. Don't be tempted to use a pressure washer though, you'll quickly destroy it!

    This should fix 90% of overheating problems.
  3. im like the complete oppersite
    my temp only stays at 1/4 of the bar and when it reaches 1/2 it doesnt stay there 4 long and goes back down
    mayb cause its winter
  4. Also chekc the water levels and water colour in the radiator. If it looses water say over a week, u might have a leak. If the colour is milky, you could of blown a head gasket.
  5. Yeah in traffic on warmer days mine will get to the red point (The fan kicks in just before it) if you are really worried about it you can flush the radiator as cammo said or install a fan switch so if your in traffic you can keep it cooler :)
  6. I'm fairly new to bike maintenance.
    Is there a link on how to change/flush the radiator fluid?

    Thanks again
  7. this will only delay the inevitable, not stop it. And you add the battery flattening problem as well.

    simple things to do are replace the coolant with fresh stuff and check radiator for blocks as said earlier.

    Make sure radiator cap seal is ok and the pressure spring is not worn out (reducing the working pressure of the cooling system).

    When stuck in traffic but not long enough to warrant switching it off, keep the revs up a little to get a greater mass of fluid flowing around - water pumps at idle on a 19,000rpm capable bike do not flow much volume or make much pressure.
  8. Hey guys,

    Great replies. How do you drain the radiator fluid from my CBR? Is it like draining the fuel bowl, i.e. unscrew a bolt?
    What kind of radiator fluid do you guys recommend and what is the mixture ratio of radiator fluid/anti freeze/water?

  9. From i know you should run a 50% mix but be sure to not get those cheapo premixes they sell at stores like supercheap etc they are not actually antiboil/anti freeze and also make to get one that have glycol in it i think, also get one that has slogans such as 'safe with aluminium components' etc

    hope this is helpful
  10. take the filler cap off, drop the bottom hose and there is usually a bleed bold in the water pump or surrounds. (same idea as an oil drain plug but much smaller - usually in the middle and not an edge holding the front face of the pump on)

    There may be additional bleed bolts in the block but you can do it fine without them unless you run a weird old model two stroke that needs different parts burped :)
  11. Back-flushing it will do it even better. Remove the radiator. Flush it from outlet to inlet, and tap the frame repeatedly with a rubber mallet or a piece if wood wrapped in rag. If it is really limed up you can fill it with a dilute solution of water and CLR, leave it for a while and then back-flush it, repeat as required.