NSR Overheating

[Evo]

Went taking my bike out today to start the running in process.

It keeps spitting the coolant straight out of the overflow. I mean everything. It did it in about 30 mins riding and i wasn't exactly pushing it(Running it in).

It's a 2001 model NSR 125.

Temp guage went off scale and ended up with steam out of my overflow. Stopped immediately and filled up. It got me home. But longterm it needs sorting.

Any idea's ?

Pressure cap seems to work ok.
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Bikes owned
1989 VFR 400 RR NC30

[baldy]

i would have thoght it was the cap that was not working, but check your waterpump.
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One day i will rule the world, just not today.

[st3v3]

Wasn't just steam, at some points, there was coolant proper gushing out of the overflow, might be advisable to bleed it at some point too, but that's up to you
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Roger wrote: Women don't get damp for clingy puppies. Get some better happy pills, hit the gym & buy a medallion the size of a dinner plate. Job done

[Evo]

lol ya st3v3. Might be a good idea.
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Bikes owned
1989 VFR 400 RR NC30

[salty21]

when you refilled it did you leave the cap off for a few mins and rev a couple of times to around 5k to get any air out the system? also im guessing you put the thermostat and sensor back in after rebuild?
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04 NSR 125(sold) ---- 03 CBR 600rr(sold) ----90 pan euro ST1100 '' ----02 CG 125
94 CB400 Super Four ---- 2000 VTR SP1 (sold) ---- 08 ninja p8f(sold, meh) ----05 CBR600rr

[Evo]

[alains]

i think you have a cylinder head gasket problem . did you fit it in the right way ? it seems that the cooling liquid is not circulating normally . the temperature in normal use never goes more than 3 mm outside the blue zone . it's also a possibility that the calorstat (inside the head) doesnot work , but i will be surprised if it was that
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the worst day fishing is better than the best day working

[roach_101]

when you filled with water did you keep the bike running as this circulates the water as you are putting it in, meaning you dont get airblocks which can cause this.

[roach_101]

[alains]

i forgot an other possibility (and i hope it is'nt this one) : when you put back the cylinder head gudgeons , if you tighten them too strongly you may cause a crack in the inner inside . this will cause the water leaking by the head nuts . if it's that , take of head and all gudgeons , then drop some loctite inside holes , refit gudgeons tightened without strenght until the gudgeon thread desappears , refit head and let it for 12 hours (time necessary to polymerization)
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the worst day fishing is better than the best day working

[st3v3]

it was leaking from a rubber pipe entering the head or radiator so after undoing the circlip, refitting the pipe and re-toghtening the circlip, all seemed fine, then it was leaking out of the overflow but only when warm(seemingly) so I thought it was bubbling up to the top of where you put coolant in, and down the pipe that way, so put a crease in the overflow so as to stop it leaking, please tell me I didn't cause any damage doing this
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Roger wrote: Women don't get damp for clingy puppies. Get some better happy pills, hit the gym & buy a medallion the size of a dinner plate. Job done

[baldy]

sounds like the pressure cap has gone, probably caused by a leaky head gasket pumping pressure into the cooling system.
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One day i will rule the world, just not today.

[Evo]

I'm going to have to take my cylinder head off as it's still overheating. Barrel steams water away within touching, it's that hot.

I'm guessing i fitted the gasket the wrong way ? It only seemed to fit one way(lined up with screw holes and general mold).

But i'll take it off and check anyway.

It's loosing the whole coolant system fill within 20 mins at moment. And yet no leak.

I did notice the other/reserve coolant tank - NOT radiator. The water was clear blue- filled up with new fluid. and no has an oil glaze to the blue. if that means anything ?
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Bikes owned
1989 VFR 400 RR NC30

[roach_101]

yeah i am sure it only fits on one way but anyhow the two cut outs on the gasket go towards the exhaust end. is your thermostat on properly or working at all coz that would cause it too overheat like this as the coolant won't be circulating. if your taking head of anyway you could check it works by placing it in hot water about 70-80 degrees celcius and it should open at this temp.

[Evo]

Took head off and found Gasket was on wrong way. Main water jackets were restricted while giving full access to the other side(rear) which has no main jacket gaps.

Stupid me.
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Bikes owned
1989 VFR 400 RR NC30

[alains]

not stupid the only one never wrong is the one who does nothing
just careless and as you see in mechanics faults are never forgiven
the best is that you found it
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the worst day fishing is better than the best day working

[Evo]