something aint right

hey im new to the Kris Ralph from a small town in Newfoundland. i recently purchased a 2003 yz450f and im almost ready to sell it again. to start things off it leaks antifreeze out the weep hole in the water pump...when its at operation temp it seems fine and everytime u shut it of its dripes a dozen or so drips. next theres a white paste like oil/antifreeze mix commin from the vent on the head cover...that magnessium cover. its about 5 degrees celius here now but its really pissing me off ...i replaced the water pump seals and still this. someone help please before i sell it

ohh forgot to mention that i just did an oil change with new filter and all new coollent.

Hey copstop.. Where you from in Newfoundland? East, West, North?

5 degrees is cold brrrrr...

I always have a little coolant come out of my bike from normal riding.

Just out the overflow. But nothing major. Top it up with a few mils everytime I start out.

Yours does sound a little strange though, I mean they do run hot but.. well anyways I hope you get it sorted and don't sell the bike because it is just too much fun..

yeah its furtest east in canada. ok i read that the white liquid commin out the vent is only condensation or something? bike was set up last 4 nites and the temperature was dipping down below 0 celcius so i guess thats nothing serious. but the leakin antifreeze is a pain in the but...always toping it up every day after a long ride

sounds like a bad waterpump shaft, mine did the same thing, he was weeping a bit and then she popped and dumped a bunch of coolant into the engine....take a look at that shaft and you might as well replace it while your in there..... Just some thoughts

it does have like ridges on it but it looked like it was suppose to be like that but i guess tahts the problem...ill order that tomorow thanks

The shaft will have one groove machined into it. Condensation in the breather hose is no big deal, but finding evidence of water under the oil filler cap or dip stick could indicate trouble.

I have the same issue with my 99 YZ400....

I am going to replace all of the internals of the water pump..

that would include the impeller shaft, all the seals and the bearing

I checked in with a couple of Yamaha service techs and they all said that if the impeller shaft needs to be replaced due to the groove that the bearing and oil seal can put into the shaft

the Thumper talk store has the impeller shaft for 20 or so dollars

before you sell the bike get a new impeller shaft and see if the problem continues

Patrick M.

well i just found out another few issues it could be.

1. wrong antifreeze

2. impeller shaft damaged

3. overflow line plugged up

good detective work..

I hope it works out for you soon.

well bys i just started her up...she dripped until up to operating temp and she stopped...i think im gonna give her another lil while and NOT keep it filled to teh brim like the manual says

That part is normal, and to the extent that the dripping during warmup is coming from the overflow tube, there's no problem. Coolant expands as it heats, and it is expected that the excess will be expelled this way. By doing it like this, you keep it at the optimum level possible. But, if you run the engine for a while, and then allow it to completely cool, you can check the level it has reached. It should be about 1/3 the distance between the top of the tubes and the filler neck. If you keep it there, you'll be fine.

When the shaft seal is weak, coolant may force past it during warmup instead of running through the overflow. That would need to be fixed.

Wrong anti-freeze? How did you manage wrong anti-freeze? All it is is glycol and water not like a certain size or something to it, or is there? If so, I am going to say I am dumb.

first off theres brand new seals on the shaft and theres no anti freeze commin out of the overflow but out the weep hole. and next the antifreeze im told ur suppose to use is NON sillicate base so it dont damage the seals in the water pump and that it dont corrode the rad.

Oh ok, I didn't think of that at first but you are right. Sorry to blurt out like that I was just confused. I run distilled water/water wetter mix in everything not street legal that I own, so 'anti-freeze' isn't what I need at all when it comes to that stuff, just max cooling.


Oh yeah and I said I would say it, so, I'm dumb.


If it has new seals and still leaks, there are 3 possible causes.

> The shaft is worn from the old seal, and is preventing the new seal from functioning correctly.

> The seal was damged during assembly.

> The seal is installed backward. The lip and spring must face toward the fluid it is to seal against, which means it has to face outward toward the impeller.

Of course, any number of these conditions can exist simultaneously.

awww dont worry about it Team...thats nuthing. the seals are in pretty sure the shaft is wore is y im gettin the problem. when i first put the seals in it was purfect for two days and then got bad but i did notice a lil wear on the shaft...ohh well spoil somemore money on it lol. thanks guys for everything!!

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