over heating cbr

aussierunner · 03-10-2008, 7:12 AM

Hi guys been a while,my sons 250 has over heating problems have changed the radiator,thermo fan and switch do these models have a thermastat any where? it only overheats on warm days and are they prone to have head gasket problems any other suggestions or remedies would be a great help.

denzee · 03-10-2008, 7:38 AM

Does it overheat going slow in traffic or while running the back roads or both? More info on the bike would be helpful. Eg. year, model, miles etc. It would also have a stat located somewhere.

MACI4LIFE · 03-10-2008, 10:50 AM

check the fuse for the fan. simple but you never know.

cbr900racer77 · 03-10-2008, 5:33 PM

Quote:

Originally Posted by MACI4LIFE

check the fuse for the fan. simple but you never know.

absolutely...start with the simple stuff. There should be a switch on your radiator, pull the wire and ground it to the frame, fan should come on if your electrical is in order. Not familiar with the 250..Follow top radiator hose (normally on righthand side of bike), it should lead you to a thermostat.

aussierunner · 03-11-2008, 6:54 AM

the bike is what we call in oz land a grey import which is a refurbished 10 year old jap import, the fan comes on most times but every know and then it will not,over heats mainly in slow speeds but will over heat anytime i am leaning towards a head gasket as the main problem but not sure give me a 954 any time

denzee · 03-11-2008, 7:56 AM

Sounds like you might be going in the right direction unfortunately assierunner, especially if it overheats cruising on the back roads. If a pocket of air (compression) gets in the cooling system, the temp senson cannot read hot air which will keep the fan from coming on when needed.
Still check the easy stuff like the others have said first, like your fan stat, thermostat and so on.
Other signs of head gasket failure could include.
-pressure in cooling system immediately after starting.
-bubbles or boiling look in cooling system.
-coolant level changes
-oily residue in coolant

aussierunner · 03-11-2008, 8:24 AM

thanks will try the thermostate next if i can find it

silvercbr1000 · 03-11-2008, 8:49 AM

flush the system and then run water wetter. it used to keep my old gsxr race bike from getting to hot on track days.