Hot CB500

[Ingah]

I've noticed my CB500 (recently aquired) can get quite hot (looking at temp gauge) - despite my reading about suggesting they should actually run abnormally cold.

Whenever the bike is stationery (i.e. in non-moving traffic) it heats up very quickly. Over the space of 30 seconds to a minute i can expect the temperature guage to hit at least half-way (and keeps climbing...)! Fortunately traffic is light round my way but i am concerned because when i went down Swansea and got in the traffic the gauge got very near the red before i parked. However, when the engine is cold this does not occur (i.e. i leave it for 30seconds to warm up but at this time the engine isn't getting hot - it's only when it's had chance to warm up abit, and then i go stationery).

I know it's an air-cooled engine, but is there some problem?

NB:

Bike is restricted to 33BHP (basically #125 jets and restricted air-intake).

Bike has Motad end-can fitted (i'm suspicious this could be causing the problem due to the restriction as-well).

Oil and filter has been changed very recently in front of me (definately done).

The fan that kicks in when the temperature gets to about half-way definately works as i've heard it going.

Edit: If the engine is hot i've noticed i can cool it down by riding nice and briskly - the difficulty being this may not be practical in a city.

That's everything i can think of that could be relevant.

[Guest]

ok,

the CB 500 isn't air cooled, at least not as in the motorcycle sense.

you have a fan, and a radiator, so your bike is water cooled much like a car.

i have an oil radiator, which means i am oil cooled/air cooled.

check your water levels, you will probably have a top up tank under the seat or a cap on the side of the radiatir, if you have an owners manual then have a thumb through it, or buy a haynes book of lies..

i suggest that your water level is probably a bit low..

[slugworth1987]

CBF500, CBF600 and CB600's run quiet hot trick is to not put a gaurd on the radiator to keep a good air flow, the CBF500+600 run well in town even in 20 min traffic jams, but they do get to the red line of temp gauge but seem to stay there but the fan does work quiet well.

i cant really tell you anything else just check your fluids (under seat?) normal operational temp for my CBR125 is mid range of its gauge but only gets there in stationary traffic in summer... winter and summer moving it stays between line 1 and 2 of 5

[Ingah]

ok,

the CB 500 isn't air cooled, at least not as in the motorcycle sense.

you have a fan, and a radiator, so your bike is water cooled much like a car.

i have an oil radiator, which means i am oil cooled/air cooled.

check your water levels, you will probably have a top up tank under the seat or a cap on the side of the radiatir, if you have an owners manual then have a thumb through it, or buy a haynes book of lies..

i suggest that your water level is probably a bit low..

 

Oops my bad - got my CG and my CB confused lol.

And cheers both, will check the coolant/water tomorrow.

[Guest]

if coolant is ok .. i suggest take it for a spin and bring it up to operating temp and then return to base and allow the bike to sit and whilst making sure that the needle does not enter the red zone ( If it looks like its very close to ride the bike to get airflow through the rad) wait to see if the fan cuts in on the rad ...

if it does all well and good

if it gets near red zone and no fan (go for ride cool bike down) and then turn bike off ....check the fuse box for fuse for fan make sure intact

if fuse is good find the fan temp switch ( generally a large brass coloured nut shaped thing on rad with two wires ( or check haynes manual for location ) and with ignition turned on ( bike not running ) bridge the two wires together and see fi fan kicks in .... if not you need to check for power to the switch first of all ( test lamp etc) if power ok there possible fan failure

if it does work i would suspect the fan switch is faulty and needs replacing

( was going to post this last night bit the aircooled bit threw me so didnt bother afterwards)

[stevie16v]

make sure your mixture isnt running too rich either. Thats another cause

[rollazuki]

rich mixture causes cooler running, not hot.

check coolant, ensure cooling fan actually works.

if fan isnt working, hotwire it to 12v, and see if bike overheats with it spinning

eventually bin it, and buy a Suzuki!

[truxx]

I think he said the fan does work.

But to get them working on the cb you just touch the wire on the rad fan switch to earth.

I would agree with the low coolant level,but failing that it may be worth doing a plug chop.

Also make sure you have enough engine oil in.

[slugworth1987]

jet wash your rad with high pressure when cool will clean it out from grit, mub, caked on crap! this will effect your cooling drasticly if fins are clogged with mug theres no air flow.

[Ingah]

Just an update:

Gave the radiator abit of a clean (no jet-washer, just with mitt and shampoo etc). No effect.

Had it looked at, and basically 2 faults:

1) The radiator has indeed stopped working properly (must've been recent as i did hear it going a while back). It can be made to work if done manually, it just doesn't come on automatically like it should.

2) Coolant level was indeed low, in fact it had practically all gone, because it's A) Leaking out of a pipe and B) I accidentally let the bike overheat leaving the engine running for a few minutes, so some coolant spurted out of the overflow pipe thingy before i had chance to kill the engine.

Refilled the system with water for now (no coolant around), and it'll be sorted out properly soon. When the original dealer bothers to send out other parts i need. If he can be bothered. The sod.

[cyberwolf]

which dealer is that

its only so i know never to use him

[rennie]

so the fan works?

the switch is at fault then!