Flushing the coolant

[sr20baby]

hey guys was just wondering if anyone knows how to bleed the coolant on a KTM 450sx 2007 model in the manual it shows you how to drain it bu taking the bolt out of the water pump at the bottom then putting it back in and refilling it but l'm not sure how to bleed it any help would be great

cheers

[norcal_hoss]

Thats all you do, drain it and fill her back up with engine ice or whatever it is your switching over.I just did my 505 today.

[loopsrider]

I asked the same question a while back.

The manual is confusing as it says something to the effect of "bleeding" the system. All they are referring to I think is heat cycling the engine and rechecking the level.... No real "bleed" proceedure... Changed mine a month or two ago and all I did was refill and haven't had any problems...

[sr20baby]

oooh ok yeh the manual is confusing cos it say to "bleed" which l didnt understand the reason l am flushing the coolant is cos l went for a little trail ride on the weekend and as soon as l get into some tight stuff it boiled over steam was pissing out everywhere the coolant thats in it now is just from factory so l'm going to add something with a stronger boiling point, should l drain the radiator with anything before adding anytihng new???

[VilleKTM]

Flush the system with water. And " Bleed " it like Loops just descriped.

[sr20baby]

because the bike boiled over can that harm the bike in anyways just after steam started coming out l just turned the bike off for abit then l turned it back on so l went to an open area to get some air flow n cool it down l checked the water level today and it was alittle low but l think the fins were still coved

[VilleKTM]

No problems. Don´t worry about it. They overfill the radiators at the Factory so those always boil over if you don´t correct the level by yourself. When you fill the radiators don´t overfill them. Leave the level 10 mm above fins. The hot coolant has to have some space to expand - otherwise it`ll just boil over again when the going gets tough.

[albertaguy]

I run engine ice in mine and have never boiled over though have heard it making noise in there after long narly hill where I was clutching a lot to get over stuff, something I hardly ever do on my xcf (need to clutch a lot that is). Anyway as has been said you likely just blew off the overfilled amount anyway. You can either add redlines water wetter to your stock stuff or run engine ice or a comparable product. Flushing would be a better description than bleeding. Drain, fill with water, run engine to circulate, drain water, add new coolant, run to circulate, check level and top up as VilleKtm says just over the fins a bit.

[sr20baby]

thanks guys l'm gonna flush it today, my KTM dealer said that out of factory they dnt really put a strong coolant in them cos over there its much cooler then say Australia where l am so they tend to over heat in the tight stuff when l'm on the track there is no problem runs beautiful my 06 KTM 450sx did the samething and over heated in the tight stuff, all my KTM dealer said was to run a higher boiling point coolant in them to stop that happening.

[VilleKTM]

And so you should ! So you´re saying the Austrian Alps are cooler in temps than Australian Desert ??

[sr20baby]

haha yeh thats whats l'm saying becuase its cooler over in austria they dont run a strong coolant in the bikes, so when they bring them over we should change the coolant to suit our conditions, and l dont ride no where near the desert but it does get hot here in summer even more so when it rains.

[VilleKTM]

I don´t know about the coolant they pour in at the factory but i too change it before i even ride the bike the first time. Just so i know what´s in there...

[L-vie]

So the SX motor does not have the bleed screw on the right side of the head like the older RFS motors?

The RFS motors can get an air pocket in the head and cause over heating problems.

I have no idea about the newer motors though.

[VilleKTM]

No. The new engine don´t have the bleeding hole. It doesn´t seem to need one.

[sr20baby]

so how does that work does it automatically bleed its self??? well l changed the coolant yesterday all l did was undo the bolt at the bottom on the water pump coolant came out not much mine u l thought more would have but they only hold 1.2 litres of coolant then put the bolt back in filled her up started it let it run for about 5 mins let her cool down and checked it the level was ok but l'll check it after a short ride where the bike is under more stress.