KR-1S.co.uk Forum

Hi folks,

So I got to run my KR1-S, I bought in October, Sunday and today a bit.
When I push the lady quite hard that the temperature rises nearly to the first red stripe after a while but cools down quite fast when I slow down.

Is this normal?

Thanks
Chris

Nn that doesn't sound right to me

maybee your temp sensor is broke


do you have the feeling that the engine is overheating or not

do you use coolant ore water in your system?

I use coolant.

It is the right one and well filled up and everything.

Could it be the water pump? But the water pump cannot pump "not enough", either it works or not, or am I wrong?

Thanks
Mouser

No you're not wrong and it could be piss in your rad and not display these symptoms.

The heads have a tendancy to warp, which causes odd cooling symptoms. I've experienced this first hand.

Does your header tank experience a lot of expansion and or pressurisation? If you haven't checked, yet, check your level cold and make sure you don't need to top up the coolant in the rad. Give it a good blast, when you see the temp rise, check the header tank. Keep a look out for bubbles too.

.
.
air pockets in system will produce local boiling - burp

but next to check would be removal of thermostat (partly drain coolant) - it is possibly corroded or not functioning (slow) to open
hence reduced restricted flow and high temperature - then finally popped open and dropped temp as flow speed up

Think I'll change the thermostat then...the system is filled up and no air in it.

Thanks
Mouser

Hi,

So as I said, I changed the thermostat..and...nothing changed.
If I push it really hard, the temp rises after a few minutes to nearly the first red line! Cools down within 2-3minutes when I go slowly.

Everything is filled up well!

What can be the problem?

The water pump?
How to test it?
If it was the water pump that wouldn't work the radiator shouldn't heat up very much should it?
It gets really hot, so I can hardly imagine the water pump not working.

Any ideas?

Thanks
Mouser

if you can try to test the engine with a tempmeter ( maybee the tempsensor is broken or the tempmeter)

The water pump is driven off the engine, so it will normally either work or it won't. It could have suffered damage to the veins, but it's unlikely. It's easy enough to check though, so I would take a look.

I would also strip the hoses and inspect the radiator closely. There could be an impedance somewhere which is causing a cooling inefficiancy.

chech that airbubles come to the top of tha rad. make sure to test when revving hard. could be that the head gasket only leaks when the combustion presure is very high.

and buy a thermometer you can put in the radiator filling gap and check the temperatures. might as well be that your sensor is sending wrong values, or the meter doesn't display them correctly.

That was what I originally suspected Jan, but apparently no bubbles.

JanBros wrote:chech that airbubles come to the top of tha rad. make sure to test when revving hard. could be that the head gasket only leaks when the combustion presure is very high.


and buy a thermometer you can put in the radiator filling gap and check the temperatures. might as well be that your sensor is sending wrong values, or the meter doesn't display them correctly.

The head gasket is not leaking at all..or do I misunderstand something?

I have a laser thermometer. I will check the temp., note the values and put them in the thread in a few day!

Thanks for the help guys!
Chris

So Yesterday I tested the whole thing.

At "normal" temp. (gauge exactly in mid.) the radiator and head have around 86-88°.
At "high" temp. (just before the first red line) the rad got around 96° and the head even around 112°.

So there seems to be a hint. Will check the pump drive and will clean the system and radiator.

But what do you think about the temp with the gauge in mid position 88° is it normal?

Thanks
Mouser

Holy shit that's hot. My race bike was running around 68° in 2012 on a hot day and that's way to hot. I'm aiming around 56° running temp for my new bike.