I have a 2008 kfx 450r and want to change the coolant in it. Curious if anyone can give me some tips on doing this as I have never done it on a quad. Is there a drain on radiator or overflow tank? petcock or something like that? also how or should I flush system before refilling?

 

Answers to your questions.
1. Yes there is a drain. But not on the radiator but it's on the bottom of the water pump housing cover on the right side of the engie.
2. Yes, there is an overflow tank on the right side under the front fender with refill cap.
3. Yes, you should driain/flush the old coolant even if it looks good because it may have lost the lubricant chemicals in it.

 

Ok I found drain on the water pump. To drain overflow tank it looks like I just take the hose off the bottom? Can I flush the radiator and overflow tank with water or do I need to use something special? Also is there any procedure for flushing the system? Just leave drain open and run water thru it is what I assume. Thank you for your help

 

Here is what I do.
> Completely drain the old.
> Add Preston cooling sytem flush fluid (from WalMart, Auto Zone, etc.) and bottled distilled water to the max.
> Ride the quad until engine gets hot (10+ minutes).
> Drain again when not too hot.
> Add distilled water only.
> Ride again until hot.
> Drain again when not too hot.
> Add 50/50 mix of coolant and distilled water.
> Be sure to use correct type coolant that is desinged for aluminum cooling system to avoid corrosion and plugging up of the cooling system. It is very important on your 400.
> Ride again until hot.
> Use hydrometer (that checks specific gravity of the coolant) and add either coolant or distilled water to fine tune. Coolant will raise and distilled water will lower the S.G.