03 CRF450 overheating!

I just purchased this bike, after about 5 minutes of sitting still the radiator overflow hose will start dripping rad fluid then steam, header glows bright red??? Even at real slow speed through twisty trails. The radiator fluid was about 15 ounces low so I topped it off and still doing the same thing after 5 minutes in the stand. I'm not familiar with 4 strokes is this normal?

This sounds fairly typical.  All bikes will overheat after idling for 5+ minutes while standing still.  The proper coolant level is with the coolant just over the top of the rad fins with a cold engine.  This allows for coolant expansion as the coolant warms up.  You also want to make sure that the cooling system has been bled to get rid of any air bubbles.

Edited by Chas_M

Yes these bikes like lots of air through the rads to stay cool. For the conditions you are describing it is absolutely normal

Do yourself a favor and dont do what youre doing. The radiators are just barely big enough to cool the engine with it moving. Remember, there isnt any fan so it just sits there and cooks. If you want to fire it up and put your gear on, do it after youve put on your boots and pants etc...It only takes about 2 minutes for them to warm up, just sitting there.

i would advise against letting that bike sit in idle for very long.  :naughty:

i let mine warm up for 30 seconds to 1 min at MAX and then kick it into first gear and putt around to let it get up to operating temp. 

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