NSR part identifying advice

[Tristan.]

Just a warning, if you don;t want to read paragraphs of mechanical ineptitude skip to the end where I get the the point.

So, nearly two weeks since I did a top end rebuild started, and I'm fairly sure I can finally see the light at the end of the tunnel.

All the movey bits came apart and went together fine, and she's running fine, apart from the cooling system, which originally I couldn;t find the tap for

Anyway, went for a run, and a few miles away from home discovered coolant pissing out, unable to find where i was coming from, and with tools lying in the garden I had to push her home and located the problem, the metal tap that joins the hose to the cylinder head was leaking.

So that gets liquid gasket'd, and I go for a more gentle ride, despite not leaking when I take her to 13k in the garden, two blocks sees it pissing through again, coolant gets bled for the third time and I slather on plenty of liquid gasket, leave it to set for a day and refill the system, coolant comes straight through the stuff

Anyway, onto my question:
So I've decided to dig up the manuel turns out when the old cylinder head came off we must of lost the thing in the red cirlce:
https://i35.photobucket.com/albums/d170/tristanthe/thermostat.jpg
later in the chapter it's refered to as the thermostat, I thought thermostats controlled temperature, not sure how that does since it's not attached to anything, anyway if anyone knows a web place that stocks em, I've been through all the usual ones, or a part number so I can get onto David Silvers that'd be awesome, cheers

[alains]

this thermostat works as a valve , it's closed and when temperature get to 70°c it begins to open and the cooling liquid can circulate to do its job . do not change that prior checking it otherwise it's wasted money (it's quit expensive).
fill a pan with water , drop the thermostat in it , then warm water on your cooker when water begins to bubble you will see the thermostat opening . if not you may change it
you can also put back the pipe without the thermostat but your bike will take longer to warm up
i recommand to use loctite 510 and pass a thin coat on each contact surface before tightening
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the worst day fishing is better than the best day working

[Phil_P]

Some thermostats incorporate a rubber seal in the body to help seal the head to the thermostat housing. Without the thermostat in place, if the mating surfaces are anything other than dead flat then you may not get them to seal. One alternative if you don't replace the thermostat would be to fit a suitably sized o ring to sit in the groove that the thermostat sat in.
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It is not enough to win, others must fail.
Moto Guzzi 1100 Sport Injection '96

[alains]

i make mine with a piece of 120g paper
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the worst day fishing is better than the best day working

[Cwizard]

i recently changed my thermostat as overheating issues, the best place for parts i have found is John Oldfiled. He's great, give him a call, it was around £35 when david silver wanted a lot more. his number is 02380 630326. He's somewhere in southampton i think, but sure he can send it. Any parts for the NSR i get from him. Also the thermostat has a rubber o rign/gasket on it, so slot it in bolt back together, job done. Dont forget to get all the air out of the system, it took me a while, but i think i have cracked it now.
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Honda NSR 125 R1 (51)
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