NC30 water pump / thermostat

[CRM]

Guys took my project for its maiden run. it got hotter and hotter and hotter.
by the time i got back it was just shy of the red and pretty warm.
rads i know are perfect, so whats your bets ? water pump not pumping or goosed, or the stat ?
obvious is to remove the stat i guess and try again without that.

[fastdruid]

Easy to test the pump just fire it up with the cap off, rev it and you'll see the water swirling and the level rise and fall slightly as you rev.

Odds are its the thermostat, are the radiators getting warm?

Druid

[CRM]

Hmm cap off and nothing, not even a ripple.
But would it make any movement even from cold with the stat closed ?

[Jas RVF]

No you would need to look when its warm as the stat stops water going to the rads below its setting and keeps the water in the engine. When it reaches the stat's temp it open to allow the water through the rads. sorry if i'm telling you how to suck eggs.
Jas

[fastdruid]

Sounds like your water pump is fscked, the setup on them is so that the water pump sucks coolent through the rad. So when you rev it and the thermostat is closed the level is seen to dip slightly (although very noticeably) as it pressurises the system upstream of the pump. As it warms up (or if you remove the thermostat) you should see actual flow, not 100% sure if you'll see any with it in before the coolant expands enough to spill everywhere, its been a while since I've done this other than on a bike without a thermostat.

Druid

[CRM]

i am inclined to agree here. the rads were warm when i parked it and i just dont think there was any flow. i have found a pump for a couple of quid, for the sake of a coolant dump and change its worth a go.
i also know the stat was working as when i cleaned the housing up i dropped it into a cup of boiling water and it opened around 5mm so enough to flow the coolant i think, plus under pressure and normal conditions i bet it would open more.

do i need to swop a gasket or something for the pump, cant remember or have the manual handy ?

[fastdruid]

Even with a fscked waterpump there should be a small amount of thermosyphon flow, enough to provide some cooling at least (and to warm up the rads).

No, no gaskets required although it is advisable to replace the O-ring.

Best suggestion is to lay the bike on the right that way you don't need to worry about oil loss.

The pump can be a bitch to get out though.

Druid

[Jas RVF]

That will teach me for not looking in the manual, i stand corrected - goes over to the corner

[Variablevalves suck]

Im not familiar with the V4 but if the water pump sits as the suzuki ones do, if you dont bleed the pump correctly they can just spin nothing over and you get symptoms as you say.

[CRM]

Peeps just to update you. dropped the stat in a cup of boiling water and zip, bugger all, not even an ouce of daylight. ok so i repeated with another stat, and side by side with the other this one opened just a couple of mm which is enough.
so thats one problem sorted.
however even after running for 20mins, water got nice and toasty on the bottom of the stat and then it opened as i felt warm come through the top hose to the top of the top rad.
but still bugger all movement, and still cold hoses and rads all on the left and cold by the pump.
guage was showing around 60 - 70 so just off the cold but evne still i would have expected a bit of warmth in the rads.
i think i will remove the outer cover of the pump and fire it up, if the impellar turns then it must be working.
yeah or neh ?