NEW BIKE

JUST GOT MY FIRST CB 500,WHEN CHANGING THE OIL THE COLOUR WAS A BAD BROWN COLOUR WITH WHITE LIQUID VEINS IN IT .COOLANT WAS NICE AND CLEAN BUT DONT THINK FAN IS KICKING IN(POSS THERMO RAD SWITCH).COULD IT BE THE WATER PUMP SEALS.I READ THAT THERE IS A DRAIN HOLE ON THE WATER PUMP WHERE THE LIQUID CAN ESCAPE FROM IF THE PUMP FAILS,IS THAT CORRECT.MINE WASNT BLOCKED.THE BIKE HAD STOOD FOR SOME TIME WITH LITTLE RUNS OUT,COULD THAT AFFECT THE OIL CONDITION.THANKS FOR HELP CHEERS

Hi,

welcome along. I'd say the white streaks in the oil are emulsified oil - if the bike has been stood doubtless some damp will have got in. Only thing to do is see how it goes on the new oil and filter. If the bike runs roughly and you get more emulsified gunk on the filler then look for a leak.
The fan takes an age to get going.
Ref the coolant. The expansion tank is on the offside in front of the shock. Check the level to see if any is going awol when the bike is running.

atb

m1

Thanks for reply.liquid does cone out from the expansion tank via the rubber hose when engine gets hot.removed the waterpump today it looks to me that it is not spinning due to it being very tight to spin there is no play in it though.but there is a build up of coolant crusted on two to three fins ,i dont know but could that mean that it has not been spinning causeing the engine to over heat?cheers for help

Hi there...

I'm guessing that if you've had the water pump off then you've changed the coolant? If you haven't then you should.

Anyway, you can test the fan in the normal way - run the bike while standing (possibly on with a bit of throttle to speed things up) for 15 minutes or so - the temperature gauge should rise and at some point past three-quarters hot the fan should kick in. If it gets to the 'red-zone' and the fan hasn't started then there is a problem - at this point there might well be coolant on the floor via the expansion tank overflow.

There are often problems with the radiator grounding which stop the fan working. You can test this by checking that the radiator is grounded using a multimeter - if it isn't then there is a problem. Luckily this can be solved easily either by cleaning the radiator mountings (so they make better contact) or by running an extra ground to the radiator from a well-grounded bit of frame.

Good luck....

Mayo in the oil can be caused by condensation if the bike had been say for a while; also check that the o-ring is intact on the oil filler cap and that it hasn't been cross threaded, believe it or not I was helping a mate sort his little 125 out and indeed the filler cap was half screwed in with a butchered thread and he wondered why the oil was milky