How do I know if waterpump is bad?

9 replies to this topic
  • Zique

Posted July 24, 2006 - 09:00 AM


Anyone know how to tell immediately if the water pump on my 426 is bad. The bike is having problems overheating.

  • Fastest1

Posted July 24, 2006 - 09:59 AM


Usually water will leak out of the weep hole meaning it is passing the seal. Doesnt affect flow necessarily but does eliminate the pressurized state which allows water to pass the boiling point. Can you see water move if the cap is off? When does it overheat? Trailriding? Or at the track? Is it a burp from overfilling or actually a boilover? Do you run water wetter or similar product engine ice, etc?

  • Zique

Posted July 24, 2006 - 02:12 PM


I'm thinking of trying some engine ice. It does boil over a bit, but it was my understanding that was normal for these bikes. It overheats to a point that it stalls out on the trail for no reason at all.

  • Ga426owner

Posted July 24, 2006 - 02:15 PM


Replace the radiator cap - this may be the culprit

  • Zique

Posted July 24, 2006 - 02:29 PM


I thought about that too.

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  • onecolumbyte

Posted July 24, 2006 - 03:15 PM


Definetly try the radiator cap before anything else. They're cheap and they get forgotton. If you've got a pressure gauge and a bunch of junk you can test them but for less than $10 just get a new one. They really should be replaced every year or so.

  • 642MX

Posted July 24, 2006 - 04:10 PM


You can also pull the pump cover and make sure the impeller blades are still attached.

  • suzuki2stroker

Posted July 24, 2006 - 08:21 PM


look for kinks in the hoses

  • Zique

Posted July 24, 2006 - 08:31 PM


Hoses are good. Shop was closed today for a state holiday. I will be replacing the radiator cap tomorrow and adding engine ice.

  • suzuki2stroker

Posted July 24, 2006 - 09:22 PM


weel, are you riding the bike hard? are you tiding really tight tech trails?

what rpm range do you run it at?

was it always doing this, or is it just recently?

the only thing that can make the water pump stop working is if the gear explodes. (you would probly find it in your oil filter)

i think you jetting might be a little lean, whats the plug look like?

if its running lean then it could just need a carb cleaning, or a rejet.

good luck

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