Apologies I know it's not a 400 but I trust the advice on this forum over the 17 year olds on 125 forums. Im riding my girlfriends tzr125 2rk around whilst rebuilding my cbr400. And I've run into an issue that I've never seen before. It's always running just under the red on the temp gauge although the coolant level is between the lines on the expansion tank but it's doing this... http://www.youtube.com/watch?v=xszQ25HB ... ata_player

I thought it was overfilled but no. I've not had chance to get the tank off yet and see if the guy she bought it off has piped it up wrong. Hopefully it's something simple. But Can anyone explain why it might be doing this?

Cheers in advance
Matt.
I'll try to get a mod to delete this once it's sorted as I know it shouldn't be here. Thanks

The system is over-pressurising. That and the running temperature suggests a blockage to me. I'd be doing a complete cooling system strip down and overhaul.

Have a nosey at the head gasket while you're prodding around the cooling system too.

Hi from the fact that the sqirt of coolant gets bigger when you rev it i would say you have a cylinder head gasket gone between the combustion chamber and the coolant jacket which is pressurising the coolant system so a new head gasket looks in order and possibly a head skim if not flat best of luck rick

If you decide to sell rather than repair, give me a shout

Has it not got a thermostat you can remove?
Regards

I'm afraid selling is not an option at the moment :p
Gonna whip the thermostat out tonight and see If it makes a difference. Maybe do the kettle test. Flush the system. Its supposedly just had the top end done so I'll re torque the head bolts. If he did it in the knowledge it was gonna be sold maybe he didn't even use a new gasket. If not I guess it's new head gasket time. My 2 stroke knowledge is very limited so thanks everyone :)

^^^
I'd be inclined to whip the top end off and have a look as they're a piece of piss to work on and parts are fairly cheap. I wouldn't trust anyone's word that it's been properly rebuilt, especially when it comes to 125's.

Just be carefull you don't snap the bolts off if you re torque. Start with the simple things first like the thermostat see how that is just leaving it out then move on to the head!! Brings back memories of when I was young!! The smell the noise, and new cranks and piston every few weekends!! Loved it!!

Regards
Mark

jim157 wrote:^^^
I'd be inclined to whip the top end off and have a look as they're a piece of piss to work on and parts are fairly cheap. I wouldn't trust anyone's word that it's been properly rebuilt, especially when it comes to 125's.

yep piece of piss,
did my nippers ns125r not so long ago
head and barrel off, new piston, rings, small end, top and bottom gaskets and a quick hone of the barrel and back together about £80