Water Pump....maybe!

[gitarninjaman]

Hello all....My bike is overheating but just when I'm sitting in traffic. On the freeway she'll stay under half on the temp gauge even when it's over 100 outside. My fan is coming on but gets overwhelmed quickly. I saw the other thread about the thermostat but seems to me if it wasn't opening it would overheat & wouldn't cool back down when I get on the open road. I figure I can pull the therm., stick it in a pot of water with a temp. gauge & see if it opens & at what temp. if it opens. What can I do to check the water pump? Do I need to pull the assembly off to check it? Any other ideas why it's overheating? After it overheats & I turn it off, I can hear the coolant boiling over in the overflow tank in the tail. I'm not about to potentially blow up a motor I just put in, so she's down until I figure this out

[Hammerhead]

What sort of coolant are you using? I've found Engine Ice lowers running temps considerably. If you have fresh coolant in the system and don't want to waste it by changing, drain the catch tank and refill with Water Wetter. You will notice a difference in temps. Water Wetter works by breaking a liquid's surface tension enabling coolant to suck more heat off the insides of the water jackets and also enabling the radiator to transfer more to the atmosphere. Also, have you properly bled all the air out of the cooling system?

[gitarninjaman]

Thanks Hammerhead. Is Engine Ice & Water Wetter the same thing? I put fresh 50/50 in when I swapped motors about 900mi ago. All I did was top off the radiator & ran it awhile & topped it again. Didn't know you could & should bleed the cooling system. How do I go about that? I hope that's all it is. A new thermostat is $38 & the water pump assembly is $185. I hate spending money on "maybes"!

[Hammerhead]

On the ZZR 12 (and I imagine the 11 is somewhat similar), you have to fill to the filler neck as the motor is running. It has to run to the point the themostat opens and coolant begins to flow. Most of the air will migrate to the top, but it helps to tap and squeeze the hoses to free up any trapped air. There is also a bleeder at the filler neck that must be opened and closed and one of the waterpump bolts needs to be loosened to bleed that area.

Engine Ice and Water Wetter are different products that perform the same function, although Engine Ice is coolant only and Water Wetter is an additive. Redline also makes Water Wetter Coolant which has the additive already.

[Claude]

On a ZX11, the manual also says that once the system is filled, to open the drain screw until some coolant drips. Be careful though as a lot can escape (I usually block the drain hole with my LH thumb while I install the screw with RH hand).

[gitarninjaman]

Thanks guys....I'll hopefully get a chance to work on her before the holiday weekend is thru. I'll keep you posted.

[zaneyzrex]

Originally Posted by gitarninjaman

After it overheats & I turn it off, I can hear the coolant boiling over in the overflow tank in the tail.

BINGO we have a bad rad cap (ill put my reputation as a bike tech on it) you can either overpay at the dealer or go get one at autozone/checkers.. just take your old one with and match it up in all measurments... ive done it multiple times.. they are hanging out on the racks...

[gitarninjaman]

Just an update. I wired in a manual switch for my fan & it seems to have done the trick. It's right where I can get to it between the locking glove box & the tank. I was able to mount it without drilling a hole in anything. When the temp gauge starts to go past half, I just flip it on & leave it on. It's been close to 100 degrees here every day & so far, no problems. Anybody know what temp the fan was supposed to cut on? Any adverse effect to my fan for leaving it on longer? I'm still going to put that water wetter in when I find it so I don't have to run the fan so much.