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Hi guys,

I have an issue where the ZXR gets hot (3/4 to full on temp gauage) when caining around, and this causes the coolant to bubble out of the overflow on the header.

It has now stopped doing this, but in order for it not to bubble over, the header tank is empty when cold

Any ideas as to cause / solution?

I have taken the rad cap off and filled it to the top (to ensure no airlocks), then ran it, and did it again.

Rad is staying full (I think, better check now, lol) but header tank is bone empty (Until she gets warm).

Cheers

its either;

normal behaviour

or

early signs of a blown headgasket

depends how paranoid you are, and how up together the rest of the bike is, what mileage, state of radiator etc etc ..

OK. So I have checked the rad level.

Needed 30ml to top-up back to normal.

Went out for a thorough thrashing (And got my knee down ) and when I got back it spat about 20ml onto the floor (overflow of header tank).

Rad seems to be at same level now its cool though?

There is also a very orangey/brown substance in the rad? Could this be due to the bike being stood up for 2 years prior to me getting it, and where the water level started to eat away at the inside?

?

shouldnt spit any out if the overflow tank is emtpy.

i had mine about halfway between max and min and it never spat any out but it would if i had it on the max line.

Wabby wrote:
There is also a very orangey/brown substance in the rad? Could this be due to the bike being stood up for 2 years prior to me getting it, and where the water level started to eat away at the inside?

?

see here mate http://zxrworld.co.uk/zxr400oc/viewtopi ... =55&t=6709

think you've answered your own question.

rover220 wrote:shouldnt spit any out if the overflow tank is emtpy.

i had mine about halfway between max and min and it never spat any out but it would if i had it on the max line.

When it gets up to temp, the header tank fills. If the header tank has anything in when cold, it pushes straight out of the overflow on temperature.

So masterofinsantity, are you saying she just needs a coolant change? or am I fecked?

Thats the colour stuff I am talking about, but the rad isnt full of it. Just a small amount in there.

Recommended steps?

Cheers

if you are lucky, its a tired radiator cap allowing the coolant to get to the overflow bottle before reaching the correct pressure

so try a new one, drain the chocolate coloured mank and re-fill with plain water and see how she goes

Wabby wrote:So masterofinsantity, are you saying she just needs a coolant change? or am I fecked?

Thats the colour stuff I am talking about, but the rad isnt full of it. Just a small amount in there.

Recommended steps?

Cheers

certainly aint gonn ahelp matter, do a coolant change but flush the rad through first then refill with proper mixture coolant.

does it look like chocolate milkshake?

rover220 wrote:does it look like chocolate milkshake?

Not really. (In the sense that I really wouldn't want to drink it)

Will get some coolant and do a flush.

Do I just take the lhs fairing off, and remove the bottom water hose, and drain that way? Then leave it off and pour water into the rad so that is goes straight out.?

Then re-attach hose and fill rad with water.
Start bike, let warm up.

Turn off, and take rad cap off - And re-top up as neccessary?

Bit of a n00b I know

take the hose off either bottom of rad or at water pump and using a hosepipe run water through as many pipes as you can.

there is a drain bolt in the bottom of the water pump housing but no doubt if your coolant is like rust then this bolt will have seized and u will probably snap it off trying to remove it.

also clean the filter near the heated carbs (if you have them) and make sure that coolant can get throught the black valve thing on the lhs of the engine.

OK, so I topped her up yesterday, and then went for a 'quick' spin.

Came back after covering 70 odd km's, and she actually spat coolant EVERYWHERE out the overflow.

She was 'boiling' also.

I noticed that at this time, the FAN WASNT EVEN ON

Could this be fan related, or a mixture of rad cap + fan + everything else?

Realy want to sort it, but the collant is £5.80 per litre, and she holds just over 2, so it's a waste of £17.40 to 'try' - I only want to do the full coolant flush when I'm sure she is fixed.

On a positive note, I had a great ride today, and kept passing the same NC30 on the same stretch or road I was hooning around. lol

Somebody mentioned to me to chuck the rad cap in boiling water.

Well I have done.

What is it supposed to do?

All it is doing it letting off a bubble every 8-10 seconds.

Any ideas?