Possible coolant loss issue UPDATED

[elrikos]

Hi guys,
just been firing up the bike after the rebuild. Not sure if i'm just being paranoid here but the exhaust seems quite steamy and i'm fearing the worst!
For the first 30 seconds or so i get a nice clean exhaust and then it goes all steamy. Not masses of steam but just a little bit. Coolant seems to be dropping slightly although to be fair it may just be airlocks coming out of the coolant as the system has been in bits. I'm wondering what to do next. I would get a compression tester on her but i don't know how to make mine fit. i've got a car type one that screws in but obviously it won't fit the vfr as the plugs are so small! The cooling systems not pressurising and the oil seems nice and clean. coolant smells coolanty rather than petrolly. I can't take her out for a good thrash as its not MOT'd yet but i'm slightly concerned about doing more damage if a head gasket has gone and i ride her to the MOT station.
Does anyone have any experience or tips i could use to check this one out? Even how to adapt my compression tester to fit the VFR (cant imagine any tester will fit off the shelf!)
She's running really nicely but has been sat for 2 years plus. I've run her up to the fan coming on and then let her cool. She starts on the button.
Cheers
Rich

[shaun1988]

my bike has also been sat for 2 years, just fitted new rads etc, how much water coolant have you used? at first i could only get about 1.2litres in, but after i had run the bike for a bit and the water had flowed around the engine i could fit a further half a litre in the top rad(not running a standard coolant bottle)

[elrikos]

coming out of a watering can (with coolant in!) so not sure how much extra i've put in. Not a massive amount. It just dropped past the fins inside before i topped it up. The more i think about it the more i reckon i'm being paranoid but you know how these things are at the end of a long build!!

[shaun1988]

lol, you should of used a measuring jug that way you would obviously know how much coolant you have put in lol, the nc30 holds 2.1litres of coolant including the expansion chamber being filled up.

[Spike16]

its probably that when you first filled it up you had an air lock somewere in the cooling system, running the engine will free this air lock and cause the lever of coolant to go down

this has happened to me everytime iv changed the coolant, a trick is when you refill it to squeeze all the water pipes to help break up any air locks, you should see bubbles come to the top of the rad when cap is off

as for the zorst steaming its probably just some liquid that has been spilt on the pipes, it can take some time to burn off so dont worry about it and it should so go away, if it dosnt thats when you need to worry

[elrikos]

well i think i've got to the bottom of this. Turns out that i wasn't loosing coolant at all (well i hope not!). What was happening was that the coolant was being pushed out of the radiator past the cap and into the catch tank. This was then being sucked bck when cold (but only if you leave the cap on!).
It appears that the radiator cap isn't sealing properly on the radiator and so the water was being pushed out relatively early rather than when it just got hot. From looking at the sealing face on the radiator it had a small amount of corrosion on it. Sanded it down but couldn't remove it all so it looks like new top rad time.
That is unless someone can tell me whether its normal for an nc30 to push coolant out of the overflow within seconds of starting (it doesn't go quick, up the tube about 1cm every 10 seconds). This is into the HRC overflow bottle not the standard one.
Cheers
Rich

[Neosophist]

sounds like you need a new rad cap!