So i just picked up a 1999 Scrambler 400 4x4 for $800. needed a little tlc, but nothing major. 4x4 works, runs fine, but it seems that after 15 or so minutes of riding, coolant starts to **** out the top of the overflow res. cap. so this happened once, and i thought i just overfilled the radiator. so today i go out, fill the radiator to the top, then fill the overflow res. to the Min. line. load up the bikes n quads, 15-20 min later of riding, its pissing out again. as i was riding i kept looking down and i could see the level getting higher and higher in the overflow tank. then it starts to boil, and pisses out. ive run out of ideas so im looking so anyone who can help me out. the radiator isnt clogged with mud. so its not that. im not sure if my fan is running though, when it was boiling over, i checked the fan, and i didnt see it spinning. im not sure what the problem is. could a line be clogged, bad water pump? im really not sure. if anyone can give me a hand id really appreciate it. also, when i turn the key to start the bike, the starter just spins over, not the motor. is that a bendix?


thanks in advance!!!!!

 

I had the same problem with mine when I bought it new in 99. first ride,,,and i was pissed. the altitude change from sea level to 8000 ft created an air bubble in the system and the thermostate wouldnt work right. Try to work the dealer with questions, and hopefully its a simple answer. Hope you like the quad,I havent replaced ANYTHING in 7 years and have ridden the **** out of it. ( Just tires)

 

This happened to me recently..... to the point where I thought my scrammy was making me a pot of tea!
Anyway.. It happened for a reason, I was bushwhacking a severly overgrown trail with my scrambler..
which i had just got running, and has a dead battery and a hotwired ignition..
so my radiator fan is NEVER spinning.. and all that hard work and very slow moving to run down trees made it un happy..
I let it cool down for 10 mins, got her out of there, and hit a few nice puddles to cool her off.
my problem is the fan isnt running.. if your fan wasnt running and it was boiling, you may have an elec problem...
start at the fan, test it with a battery, and work your way up to the thermostat and circuit board under the hood..
make sure you battery is good also..

clean the **** out of the radiator as well, and try to do 20 mins of driving where you are moving pretty good (air cooling)
and see if it boils .
best bet is to fix that fan, it should be running!

 

if you ever found an answer pleeeease lemme know cuz my 99 scrammy doin tbd same