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NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Sun Jun 21, 2009 7:20 pm
by mavrick_001
Hi all, started the baby after 3yrs last night, makes a hissing noise (Releasing pressure) when turned off and also radiator seems to get hot at the sides quick, any ideas, also petrol coming from selctor, (The old one did this, I put another on and same thing any thoughts???) Cheers Mav
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Sun Jun 21, 2009 8:42 pm
by mavrick_001
Anybody??/ Please............. I'll beg if I have to

I'll even

Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Sun Jun 21, 2009 9:01 pm
by Matchlessman
Have you checked the coolant level?
If its been stood for 3 years, its probably worth doing a complete fluids change on it.
Possibly the radiator cap rubber is perished? Have a good check over the whole cooling system looking for perished hoses and leaks etc.
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Sun Jun 21, 2009 9:51 pm
by mavrick_001
Thanks for the reply, I replaced the coolant and oil before firing it up, air filter, fuel filter etc. The last time I used it (Before storage as it were) it was backfiring (Art can) I've put the standard can back on for now, still pops a bit but I'm guessing that's just because it's been stood. The pressure hissing noise sounds like it's coming from the filler cap, altough I've just put it back on. I hadn't really given it much attention....
It seems to get hot in a matter of about a min, I'm woundering thermostat stuck??? I've squeezed the pipes for airlocks etc but it's still hissing it's titties off...... any thoughts continued???? Many thanks guys Mav
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Mon Jun 22, 2009 1:04 am
by greggo
If it has been sat for 3 years it could have any manner of crap in its cooling system. Run a good flush through it, maybe even open up the water pump and thermostat to make sure they are okay. Give the radiator itself a good long thorough flush.
It also sounds like you might need a new filler cap.
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Mon Jun 22, 2009 2:28 pm
by drifterwannab
would a Dead headgasket usualy causes the cooling system to get hot quick and also produce the hissing sound?
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Mon Jun 22, 2009 7:11 pm
by cbr_veze
yup i have heard a duff head gasket can boil coolant. maybe a compression test will give you an indication to whether the head gasket is gone or not?
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Tue Jun 23, 2009 8:31 pm
by mavrick_001
Oh bugger!!! I liked the sound of the filler cap, that was much more promising lol!!! Headgasket could probabally be a right bitch and expensive....... quick where's me haynes!!!! I'll have a look in at a couple of bike shops I used to go to tomorrow to see what the damage will be of a pressure test (£££ me thinkin!!!) Cheers for the replies guys, your stars

Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Wed Jun 24, 2009 7:56 am
by LozVTR
It could be the engine thermostat.
I had to remove mine form my SP1, It jammed closed causing te coolant not to flow around the engine.
The hissing could be because of the pressure build up in the rad, so the seal may have blown on on your rad cap.
My SP wasnt so lucky and the first thing that went was one corner of the rad.
I am only suggesting this as an option so please dont take this as gospel.
Re: NC23 HISSING SOUND WHEN TURNED OFF AND GETS HOT QUICK
Posted: Wed Jun 24, 2009 12:53 pm
by mavrick_001
Cheers Loz, I'll take the termostat out to night (If the missus will let me out to play) and try it in water to see if it works.... I was kinda fingers crossed it was this, will also check on the rad cap and probabally order a new one to be on the safe side...... Why is it we all have to play with things ourselves lol....... I guess it's all part of the fun!!!!!

Ohhh I've just noticed some new smileys!!!! Now nobody call me a

or I'll overfill me diesel tank lol.... cheers for all the help guys, will let you know how it goes..... missus permitting
