why does my 86 ninja 600 keeps overheating. i'm lost and cant aford a dealer?

Question

i have a 86 kawasaki zx6 ninja, its liquid cooled, it runs for about 15 minuts then will start overheating,the water pump works good and circulates the water,the head gaskets fine, i flushed all the lines and radiator,ther are no cracks or leaks anywhere, i replaced the thermostat, but stays the same,if i run it without the thermostat it runs about 30 minuts before startin to overheat. i'm at a loss, i'm used to the old air cooled bikes so this is new to me. please help soon i need this bike its my only transportation.

yes the electric fan works as soon as it starts getin hot it kicks in and stays on,
it will overheat wheather its just idling or when i ride it.

yes it is overheating were it boils over then it comes out the overflow tube, steam and all, i run water in the radiator rite now, the headgaskets good because it runs 150#'s of compresion in each cylinder. yes i've let it run so air can come out.

Answer 1

It sounds as if you may have a blockage somewhere.

Have you tried any of those radiator flush chemicals?...remember to make sure they are safe for aluminium.

Have you checked the radiator fins behind the front wheel. Possibly those are clogged with dirt, bugs, etc.

If none of these solutions is viable, then maybe you have a blockage in the engine block somewhere. This is not a good thing as engine disassembly is needed to correct it.

One other thing you might want to check first is whether your temp sensor is working. I'm doubting this would be the problem, but you never know. It may be registering a higher temperature than is actually present in the coolant.

Answer 2

as mentioned above make sure radiator fins are not bent over or blocked with dirt, mud, bugs. you might have to take the radiator to a radiator shop where they can soak out the radiator - since it might have calcium deposits clogging the tubes (ordinary flushing will not remove this stuff). if everything is correct with the cooling system - there is one other possibility - and that is a blown/leaky head gasket. under firing pressure hot gas may be forced by the head gasket and into the cooling system. this overloads the cooling system and it cannot keep up. you need to have a compression test run to see if any low cylinders.
also - what do you mean by "overheating"? is it actually steaming and burping out coolant (that is overheating). it is common for sport bikes to run in the 200-220 at low speeds and idling in traffic. when you are cruising at 60-70 it should probably be under 200 (if everything is ok). since the cooling system is pressurized (assuming your pressure cap is working) - and you should have 50-50 antifreeze - it will not boil over until about 250 degrees.

Answer 3

When you changed the thermostat did you top up the radiator with water or coolant? Did you run the bike in an upright position for about 30-60min with the radiator cap off to allow the air bubbles to escape?

I had something similar happen to my Blackbird, it was a sensor. I took it to my mechanic, and was fixed right as rain.

I hope you find out what the problem is, its a bummer not to have your bike there when you need it.

Stay Upright.

Answer 4

Does it have an electric fan? If so, make sure it is kicking on. Is your overheating problem coming from idle or running?

Answer 5

If you're running straight water, of course it's going to over heat!
Why do you think they call it "coolant"?
Don't use straight water.
Use anti freeze with a mix ratio of 50/50 and rated for aluminum engines.

Answer 6

CAll every local tech school who teaches motorcycle repair and see if the will fix just for the cost of parts.

Answer 7

your radiator is probably clogged and or you are running lean more likely the radiator needs to be replaced

Answer 8

thermostat maybe, thermo switch