www.zxrworld.co.uk

well as you have guessed for the last few years I have only owned strokers so forgive the login, but this is what I use on some other forums. Anyways In need of a road bike this year I ended up buying a ZXR400H1 & ZX4, for less peanuts than what a monkey would eat in a day, I always wanted a ZXR at 17, and couldn't afford the insurance so I guess i'm having my mid life crisses at just 27, its insulting that the insurance than would have been £2900 and now its £82.90

I bought these as projects and the problem that I can't find in the forum is alternative thermostats (somebody called them water valves), the water on the ZX4 isn't circulating very well, the stat seems a bit snappy, I have already been and bought a thermostat which I will play with tonight comparing the two in hot water, but I was wondering has anyone fitted a stat from something else, one that would open earlier (at lower temp).

I have already checked the 400 models the ZX4 to the L9 run the same stat which suprised me as they do have a reputation for running hot

for example in my race stroker I binned the 67 degree oem one and fitted a 50 degree one from a snowmobile, the stat opens sooner the temp fluctuates less & everything stays cooler

PS forgive me for not reading the manual yet which is I guess is on the forum ?, but where is the thermostat?

also does any know what temp the fan should switch on? so I can test the resistor in the front of the rad?

Hi welcome to the forum, you could always remove the stat altogether, just means it would take longer to warm up? you can see the thermostat herein the microfiche.and manuals are available here

in short, it's under a cover on the back of the cylinders, just below the carbs.

intriguingly, it's the same cover on L and H models but bolted on the other way round because of the hose routing.

tested the resistor in the front of the rad by sticking it in the kettle, still won't allow continuity, so will be buying one of those.

the fan works well as I tested this with a trusty split pin

masterofinsanity wrote:Hi welcome to the forum, you could always remove the stat altogether, just means it would take longer to warm up? you can see the thermostat herein the microfiche.and manuals are available here

never just remove the thermostat on a bike baz, the water flows too quickly without it for the rad to extract the heat from it .. it'll take longer to warm up, then overheat

s'what ive been told anyway.

used to do it on my old escorts mate, didn't realise it would cause a problem with a bike?

yeh, ive done it on cars too.. i guess bikes differ because of the revs involved and the fact that the water pump speed is directly proportional to engine revs.

zimm wrote:yeh, ive done it on cars too.. i guess bikes differ because of the revs involved and the fact that the water pump speed is directly proportional to engine revs.

nail on the head there, and frankly, removing the stat is a gay bodge anyway.

The thermostat serves one function it restricts water flow to decrease warm up time. When the bike is up to temp the stat is open and it stays that way until you stop the engine and it cools down

All my ZXR race bikes have the thermostat removed..............never overheated one yet so I'd reject the high speed water flow over heating theroy.
If anything my ZXRs are over cooled............. on a cold race day I'd have tape covering part of the rad to keep it that little bit warmer.

In conclusion remove it and chuck it in the bin

fair enough, ive never tried it but the theory seemed sound, so i passed it on

could be a different story on a road bike though, low speed situations where there's minimal airflow over the rad ?

cargo wrote:The thermostat serves one function it restricts water flow to decrease warm up time. When the bike is up to temp the stat is open and it stays that way until you stop the engine and it cools down

yeh, but it still acts as a restriction when its open, its not like it disappears.