View Full Version : water pump? maybe

04-22-2015, 10:40 PM
Had a problem with 03 gsxr 750 like the buggy uns cool sitting still but when u get moving like rpm wise the bike heats up. I thought engine runs hotter sitting than moving. Anyways

So i loosen the bolt up on the thermostat housing on the engine (Bleeder bolt) when idling it shoots out water. but when i rev it up water stops coming out. Is this correct

04-22-2015, 10:43 PM
Are you sure the fan is blowing in the correct direction? Have to got all the air out of the cooling system? Is the cooling system full?

04-22-2015, 10:52 PM
Fans correct. Another thing if i take the cap off the radiator with the engine off, The fluid drains from the overflow and water starts running out the radiator

04-22-2015, 11:19 PM
Whats ya thermostat like ?
Missing, stuck open ?

04-22-2015, 11:21 PM
does it get hot driving it?

04-23-2015, 12:15 AM
I will check the thermostat being stuck open. I have a new thermostat that turns the fan on at 210 and cuts off at 202. But while driving the temp will get up to 225 then wont go back down until you let it sit and idle because if you keep getting into the rpms the temp wont come back down

04-23-2015, 12:16 AM
prob higher than 225 i just pulls over and let it idle lol. STRANGE YES I KNOW

04-23-2015, 12:34 AM
I will try to bleed the cooling system to see if there's a air pocket. Will post back and let u all know

04-23-2015, 01:35 AM
I think the stock temp for the fan to come on is around 210 or 215.

225 isn't hot.

And the thermostat and the thermo switch/ sending unit are 2 separate things. The thermostat restricts the flow of coolant and the thermo switch/sending unit turns the fan on and off.

04-23-2015, 02:38 AM
Ok thanks will go over cooling system and thermostat. will post back

04-23-2015, 06:12 AM
Is this a brand new build or is this a new problem?

04-23-2015, 07:23 AM
look up what stock is. It should tell you what stock temps are. on mine it sits right at 180 and it goes up to 207 but thats after me running it super hard.

04-23-2015, 01:45 PM
Those gixxers ran the fan between 220 and 212F. How many hours are on the motor? Any idea on the coolant used throughout its life? Ive heard of one or two motors with degraded impellers.

It sounds like a blockage to me, if the impeller is pulling a vacuum at higher rpm. Does the cooling system build pressure?

04-23-2015, 01:53 PM
225 isn't hot to me but I do live in south fl.

04-24-2015, 02:44 PM
Thanks all for the help i found the problem the thermostat on the engine has to be installed with the dongle upright. So i replaced it and installed it the correct way. bled the air out and it cools like it supposed to runs around 207 degrees. thanks again

04-24-2015, 02:47 PM
And normal fan cut on temp is 220 i believe for that motor but i purchased a nee thermo switch for the fan it cuts the fan on at around 207 cuts off at 200