Checking Cooling System

[Pooh_Bear]

Yesterday I was out spraying fence rows and was almost finished.
I pulled up into a corner and had to back out. I put it in reverse
and looked down at the instrument panel to verify the reverse light was on.
I noticed the overtemp light was on. I shut the engine down immediately.
Soon as I shut it off, it was like something popped open and coolant overflow
tank filled up and started spewing coolant out of it. I was only a couple of
minutes from home so I sat there a while and let the engine cool off. Then
I started it and drove it up to the gate at the road (30 seconds tops). Then
I sat there again and let it cool off some. Then I opened the gate and went
out of the field and closed the gate and drove it home. (30 seconds of run
time tops). The electric fan is on a switch for me turn on and off. I turn it on
soon as the engine warms up and then just leave it on. It was turned on. But
when it overheated the fan was not working. After sitting for a couple of days
I tried it today with the engine cold and the fan worked fine. Not sure what
the problem with the fan was, but it seems to be working.

I was doing a lot of driving at slow speeds, and in high grass.
I'm not sure why it overheated. I checked out the radiator today and it
looks ok but could use some cleaning. Need to blow it out. I thought maybe
the grass had stopped up the radiator fins but no, it was clear enough.
So I really don't know why it overheated.

While I have the front rack off of it and can get to everything I want to fix
the thermoswitch for the fan, and I want to make sure the water pump is
working. How do I check the pump. I used to check cars by leaving the cap
off and starting the engine. Soon as the thermostat opened you could see
the coolant circulating in the radiator. Is it the same for an ATV.
Is there anything else I should check while I'm at it.
I plan on flushing it out and putting in fresh coolant.

And while I'm at it, where is the thermoswitch for the fan.
The manual says there is two, one for the fan and one for overtemp light.
I found one of them which I believe is for the light.
And where can I buy a thermoswitch online.

Thanks in advance for the help.

Pooh Bear

2001 Yamaha Kodiak Ultramatic 4x4 400

 

[Pooh_Bear]

I found my problem today. The toggle switch went bad.
The switch was only working intermittently.
Apparently it decided not to work that day and the engine overheated.

I flushed out the cooling system and refilled it but
I really do need a parts source for the thermoswitch.

Thanks.

Pooh Bear

 

[kenmac]

try parkeryamaha.com. That's where I buy parts. gooood prices

 

[Pooh_Bear]

I'll take a look at them. Thanks.

I replaced the toggle switch today.
So I'm back up and going again.
But I really do need to fix it correctly.
It's too easy to forget to switch on the fan.

Thanks.

Pooh Bear