Beta Rev 50 - fan doesn't come on - test thermostat?

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keithj
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Beta Rev 50 - fan doesn't come on - test thermostat?

Postby keithj » Mon Jun 15, 2009 6:04 pm

Hi folks,

With my daughter's Rev 50, I don't believe I've ever seen the fan running.
Now admittedly the last trial was a cold day, and she doesn't exactly rev the life out of it.

I jumped on it today for 10 minutes, rode it around the back yard, up hills, etc. No fan. Again, a cold day.

The fan does work, when I short the two connectors together.

Can the thermostat be tested? Or just put a new one in?


Keith.

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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby PA » Mon Jun 15, 2009 7:12 pm

keithj wrote:
Can the thermostat be tested? Or just put a new one in?

Put the thermostat in a pot with it connected to a multimeter then bring to boil. Should come in before it gets to boiling.



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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby keithj » Mon Jun 15, 2009 8:42 pm

Nice one, thanks PA.

Tested both the suspect one from the Rev 50 and a known working one from a Rev 80.

Both triggered at around 70 degrees C.

So I guess the 50 hasn't got itself hot enough yet! Maybe once winter disappears...


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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby gmandas » Tue Jun 16, 2009 5:28 pm

Hi Keith,

Reading this I recall having two dud thermostats on an '05 Rev 3 and a suggestion of a "bad batch". Yours is an '06, but it would pay to keep an eagle eye on it if at all suspect.

Cheers,
Greg



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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby David Lahey » Tue Jun 16, 2009 6:37 pm

Keith I'm not familiar with that bike, but liquid cooling systems usually have a thermostat in the water flow path that stays closed until the motor warms up. If yours has had this thermostat removed or if it is stuck open the motor will be very slow to warm up and in some conditions it might not get warm enough to cause the fan switch to close. If you have a non-contact thermometer you can see how warm the coolant is getting by measuring the temperature on some bare metal section of the coolant path (like the head). It should get up to 80 degrees within a few minutes of use.


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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby Duncan » Sat Jul 04, 2009 9:45 pm

Hi All,
the above comments on the thermostat blocking the water flow when cold is correct but the few water cooled two strokes I have worked on do not have a thermostat to block water flow. The pump runs from start up because the impeller is on the crankshaft and the water flows while the engine is warming up.

The Temperature switch to run the fan should switch as described higher up, First if the switch is mounted in a rubber hose (no earth) some Gassers i have seen, then the switch must have two terminals. so put the OHM meter across these two connectors while warming the housing and switch. The terminals and meter probes must be kept dry. With the thermometer measuring the temperature and the Ohm meter showing high resistance, will switch to low resistance when warmed up.

Alternately the power can supply the fan in and out. The single wire out, goes to the switch (probably mounted in the cylinder head) which will earth when the switch toggles to low resistance.

If you don't have it sorted Keith let me know and I'll test Andrew Beta and let you know.


Hi all, ride safe & have fun
duncantreller@iinet.net.au

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Re: Beta Rev 50 - fan doesn't come on - test thermostat?

Postby jmclean » Thu Jul 09, 2009 9:24 pm

My son used to have a Rev-50. Right from new, the fan very seldom came on, and he wasn't averse to giving it some stick.
We live in Brisbane and seldom go out in the cold :)

Considering you've successfully tested the fan and thermostat, and our own experience, I suggest there's nothing wrong with your bike.

Regards, Jim




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