leaking coolant from overflow line normal?

i got a 06 yz450f i picked up used,everything seems to run perfect and smooth but yesterday i was giving it a good beating in the woods for about 30minutes straight when i stoped to do a clutch adjustment when i noticed some anti freeze coming out of the overflow line for the radiator???i took it home and let it cool,when i opened up that rad cap it was still pretty full but deffinatly had some missing...any ways i noticed i didnt see a overflow jug so is dumping some anti freeze normal?? sorry if its a dumb question, im new to thumpers:banana:

ya its normal especially if u let it idle for a little bit

They over heat fast, but its also important to note that the correct level of coolant is when its just full enough to cover the radiator core. If you fill it to the bottom of the filler neck, thats too much and it will blow it out.

They over heat fast, but its also important to note that the correct level of coolant is when its just full enough to cover the radiator core. If you fill it to the bottom of the filler neck, thats too much and it will blow it out.

well thats probably it...when i bought it i "thought" it was low on coolant so i filled it up!...how do you keep em running cooler?:worthy:

well thats probably it...when i bought it i "thought" it was low on coolant so i filled it up!...how do you keep em running cooler?:worthy:

Its a common mistake.... but it doesn't hurt anything either. YZF's typically won't boil over if you have some air flowing thru the radiators.

how do you keep em running cooler?:worthy:

Keep them moving, or add a battery powered fan for the tight spots.

There's no harm in overfilling, other than you loose the small amount of excess coolant. At least that way you know you have enough. The level should stabilize right about at the top of the tubes. You might consider a recovery bottle if you're going to be doing a lot of this sort of thing.

i did some research and found you can make a recovery bottle..but wouldnt i be easier to just to buy one new from a older bike that used them?? i do plan on doing lots of trails and woods riding....maybe i should bought a WR..i think i would of rather had a WR!

i did some research and found you can make a recovery bottle..but wouldnt i be easier to just to buy one new from a older bike that used them?? i do plan on doing lots of trails and woods riding....maybe i should bought a WR..i think i would of rather had a WR!

You can easily mount a recovery bottle from a WR. I picked one up on eBay for $10. All you have to do is cut a slit in the fender for the mounting tab and then run a tube from the rad to bottle. I ride really tight, technical woods all the time and it gets HOT. The bottle catches all the overflow and then it gets sucked back into the rad as it cools down. I'd run my rads dry if I didn't have the bottle.

You can also do some other things to keep the boilingpoint lower. Here is what most/ a lot GNCC and Enduro racers do

different pressure Radiator cap

Boysen Super Cooler waterpump impeller

Evans High Performance NPG Coolent

thanks for the tips guys! i got the fo-fitty all tworn donw now just to go over it and greese everything up..ill pick up the coolant and jug..i also see if the cycle shop has that boyseen water pump impellar in stock

thanks for the tips guys! i got the fo-fitty all tworn donw now just to go over it and greese everything up..ill pick up the coolant and jug..i also see if the cycle shop has that boyseen water pump impellar in stock

You need the cover with the impeller...It has bigger/longer blades than stock...

Not cheap, around $180 bucks...Check ebay...

yea nuthin from boysen is cheap! id rather spend the $180 now rather then cook my engine when im blasting trough the woods for a few hours straight..ill probably forget to stop and check the coolant!

If you do a lot of stop and go riding, tight woodsy stuff, look into the battery powered fans...The Yz's definitely like to keep moving...

Also, use a high end coolant (I'm trying out the ZipTy racing coolant now, seems to work well)...

..i also see if the cycle shop has that boyseen water pump impellar in stock

Don't waste your money. I have one and have noticed no change in engine temp or how fast it boils over. I used a pyrometer before and after the install, I can't recall the temps, but it did absolutely nothing.

LOL!! atleast it did look cool:lol:

LOL!! atleast it did look cool:lol:

Oh yes, it does look cool.... it just doesn't do anything..lol. I bought it used and don't have much money in it, so its not a huge deal I guess.

The fan will solve your problem if you frequently overheat. Cheapest and best.

were do you find the fan at? is it a purpose built kit?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now