Intruders-Alert

Hey everyone I need some input here, and I may just be paranoid but my cooling fan never kicks on even when the bike seems blazing hot. I rebuilt the whole bike last year into a cafe racer and since then I never noticed the fan kicking in. Ivery tested the thermostat and it is stuck open, it still opens fully at the correct temp but never fully closes. Will this cause the system to run off enpugh to never let the fan run?

The fan rarely kicks in om these as they are air & water cooled. If you get into a traffic jam in very hot weather then the fan will possibly kick in. I live in Thailand so most of the time it's hot and the traffic downtown Bangkok is a bloody nightmare so I hooked up the fan to be on permanently.
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Ic well you don't by chance happen you know how to check to make sure the water pump is operating properly

Pull the rad cap off when she is cold, start her up and let her get to working temp, you should see the water flowing past the opening of the radiator.
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Lechy wrote:Pull the rad cap off when she is cold, start her up and let her get to working temp, you should see the water flowing past the opening of the radiator.
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If you put the front wheel on a block, to raise it a bit, this will expel most trapped air, too. BTW, if there is no trapped air, you will probably get coolant on the floor when it heats up - top it off when the engine cools down again.

How serious of an issue is the thermostat being stuck slightly open?

Jared_ka wrote:How serious of an issue is the thermostat being stuck slightly open?

Well, if were easier to replace, I'd replace it. But, it just means the engine will take a bit longer to reach operating temp; if your typical ride is more than 5 miles, you should be OK, IMO.

LH side of bike rear of the clutch slave cover is a small chrome cover, 3 nuts and 1 bolt. This is the water pump cover, disconnect the hose, remove the cover and the stat is inside, Be careful, the sealing gasket is O ring style and can easily get trapped and squashed when replacing the cover.
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I've got the water pump cover off the bike along with the stat, can I momentarily run the bike and see if the water pump spins or would that be a bad idea?

All you need to do is to try and turn the pump by hand, if it turns then you have a broken chain behind the clutch cover or the pump shaft key has broken.. If it doesn't move more than enough to take the slack out of the chain, it's OK.
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Awesome thanks for the help

Jared_ka wrote:I've got the water pump cover off the bike along with the stat, can I momentarily run the bike and see if the water pump spins or would that be a bad idea?

Running it for a few seconds wont hurt anything.

hillsy wrote:

Jared_ka wrote:I've got the water pump cover off the bike along with the stat, can I momentarily run the bike and see if the water pump spins or would that be a bad idea?

Running it for a few seconds wont hurt anything.

I think trying to turn it by hand is a better test, though. The key can be broken, but still turn it when there is little or no resistance.

WintrSol wrote:

hillsy wrote:

Jared_ka wrote:I've got the water pump cover off the bike along with the stat, can I momentarily run the bike and see if the water pump spins or would that be a bad idea?

Running it for a few seconds wont hurt anything.

I think trying to turn it by hand is a better test, though. The key can be broken, but still turn it when there is little or no resistance.

Yeah, true.

If it was my bike I'd do both.