derbi gpr 2007 cooling system problem

[arron2012]

[color=red]i have a 2007 derbi gpr 50 and it keeps building up pressure and blowing pipes, ive solved the pipe part and now it just sizzles and bubbles in the bottle and comes out of the cap from the bottle, but it only does this when rode i could leave it ticking over and will work perfect but soon as go for ride it leaks and when i stop its just sizzling and leaking everywhere, do you have any ideas please?[color=orange][/color][/color]
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A Barker

[P.]

Hows your head gasket doing?

[truslack]

Is the headgasket leaking? What does the temperature guage show?
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Current: Suzuki RG 125 Gamma, Honda H100, Triumph Tiger 800XC, Suzuki SV650 (minitwin)

[arron2012]

the head gasket is fine everything working apart from just sizzles and comes out the cap?
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A Barker

[arron2012]

and the temp light comes on when i ride it but ive flushed the cooling system and filled it all again and its taking quite abit of coolant and its going through all my pipes fine untill i ride it for about 5-10 mins
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A Barker

[Noxious89123]

Thermostat stuck closed? Blockage somewhere maybe?

Could be airlocked, or even a dodgy water pump.

I wouldn't ride it with the temp warning light on until you've found the cause of the problem. You could seriously damage the motor if it's overheating.
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'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[P.]

Could remove the thermostat, makes it warm up slower but hey.

While its out you can test to see if it works.

Also you may need to bleed the system properly.

[arron2012]

i dont have a thermostat in it i have a performance top end on and they use a washer thing:S, and how do i flush the cooling system propperly?
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A Barker

[P.]

[arron2012]

I leave it for about 10 mins while get ready but I think it's a air blockage somewhere as I've just checked coolant and it's half full but the temp light came on when road it so it can't be pushing all the way through? How do I drain the cooling system properly? Thanks for the help
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A Barker

[arron2012]

I mean to flush all coolant through and get rid of air bubbles??
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A Barker

[P.]

Drain it fully.

Remove water pump and check that its working.

Fill it back up whilst squeezing the pipes and the radiator cap off, when it reaches the top of the radiator, put cap back on and sit on the bike with front brake on and rock it left to right constantly for about 30 seconds, re open cap and repeat the above, squeeze and refill. Then keep repeating until its done. Unsure on amount of water but I wouldn't go filling it to the top.. My CBR125 was around 1.5 litres.

Turn bike on and continue to squeeze pipes, they should get harder when it gets warm.

That's basically what is considered the GPRs bleeding process Basic but works eh!

If that still doesn't solve the issue, the general consensus is warped head, shit gaskets or badly rebuilt.

[arron2012]

ok cheers ill do it tomorrow and keep updated to see if works:)
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A Barker

[arron2012]

I did it all and took like just under 2 litres witch is good as last time didn't even take a litre but it's still leaking out the cap from pressure I checked to see if the pipes are hard when running and there not I can't put them in and out, there's 3 pipes from the radiator one at top that comes from coolant tank one on the right at the bottom that goes to water pump witch it working fine, and one at the left that goes to my cylinder head and all was soft so it can't be flowing through?
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A Barker

[P.]

Check water pump.

[arron2012]

waterpump is working fine?
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A Barker

[Noxious89123]