2003 crf450r overheating. please read!!

i was riding my 450 and looked down to the engine and stuff to check it over really quick and i noticed that steam and i think coolant were coming out of the hose at the bottom of my bike. im not exactly sure on what to do. this is a subject that i know nothing about. will someone please tell me what to do? i would appreciate it more than anyhting. thanks a lot.

Faxon

Its kinda hard to say at this point! Were you going real slow? Was it warm out? Now that the motor has cooled off, how much fluid is in your radiator? Have you changed your radiator fluid ever?

.. don't stop. it's gonna overheat farily fast and some coolant will puke out of the 1.1bar rad cap.

Which hose was blowing the coolant? Was it a clear hose?

i was riding my 450 and looked down to the engine and stuff to check it over really quick and i noticed that steam and i think coolant were coming out of the hose at the bottom of my bike. im not exactly sure on what to do. this is a subject that i know nothing about. will someone please tell me what to do? i would appreciate it more than anyhting. thanks a lot.

Faxon

i had the same problem. i bought a 1.6 kaw radiator cap. and in the warmer months i'm using the engine ice coolant. this combo has served me well in the tight stuff where the bike doesn't get the airflow it needs. one of the 450 junkies has aftermarket radiators, and he says they work well. when i get some more $ i will do the upgrade. stronger rads w/more capacity. you could check the waterpump seal, bearing, shaft ,and impellar to make sure every things cool. :thumbsup:

ok, i wasnt gettin out of first gear. (if it helps at all i have 14t and 51t sprockets). it was about 70 degrees out and i got home checked the coolant level and i couldnt see any. i flushed the system and not much came out. there is nothing coming out the weep hole so my seal and shaft are good. ands yes it was coming out of the clear hose, the steam and drips of coolant. after i flushed the system i rode it for a bit (about 30-45 minutes[then i wrecked and it put an end to the riding for the day, wet wood is very slippery]) and it didnt seem to over heat but then again i dont think i rode it long enough. i have a new clutch lever coming which broke when i wrecked but thanks for everything! if i have any other problems ill be sure to let you know!

ok, i wasnt gettin out of first gear. (if it helps at all i have 14t and 51t sprockets). it was about 70 degrees out and i got home checked the coolant level and i couldnt see any. i flushed the system and not much came out. there is nothing coming out the weep hole so my seal and shaft are good. ands yes it was coming out of the clear hose, the steam and drips of coolant. after i flushed the system i rode it for a bit (about 30-45 minutes[then i wrecked and it put an end to the riding for the day, wet wood is very slippery]) and it didnt seem to over heat but then again i dont think i rode it long enough. i have a new clutch lever coming which broke when i wrecked but thanks for everything! if i have any other problems ill be sure to let you know!

it only takes a few moments to have a significant amount of coolant overflow if your stopped or riding slow enough the motor overheats. The 1.1bar cap is a bit wimpy IMO for tight woods riding, but you simply can't stop. Even shutting the bike off is worse if it is real close to boil over, than to just keep moving (in my experience in the past 5 yrs of woods riding the crf450). I paid $20 for an "Outlaw" 1.6bar rad cap and that helps.. but won't prevent all boil overs. As those that know more than I have pointed out, running a higher psi cap than that could be trouble. I would throw the 13t front sprocket on if your in 1st gear a bunch. Not that it will have the bike rev any higher, but it may be a bit higher rpm when your at your slowest in the really tight stuff. As your speed picks up, can try the 14t front again..

Spending money isn't a favorable option, but i will say i got a set of oversized rads for my "new-to-me" 2008crf450. (see a thread i started recently). They hold 50% more than the stock rads, roughly 30% more total coolant.. I have a thermometer strip on the top of the left rad, it never got above 221F on the strip even stopping for 45 seconds or so.. and i have my bikes idled up around 3,000rpm. It was 90F in the shade today, and i put 2.2hours on my hour meter. I am very impressed with how the $100 set of oversized rads work.. and i had been totally against getting them before. Firm believer in em for tight woods use on a crf450 in hot climates like FL where i live.

ok, i wasnt gettin out of first gear. (if it helps at all i have 14t and 51t sprockets). it was about 70 degrees out and i got home checked the coolant level and i couldnt see any. i flushed the system and not much came out. there is nothing coming out the weep hole so my seal and shaft are good. ands yes it was coming out of the clear hose, the steam and drips of coolant. after i flushed the system i rode it for a bit (about 30-45 minutes[then i wrecked and it put an end to the riding for the day, wet wood is very slippery]) and it didnt seem to over heat but then again i dont think i rode it long enough. i have a new clutch lever coming which broke when i wrecked but thanks for everything! if i have any other problems ill be sure to let you know!

in addition to the rad mods, i started using the torco 15w 40 in the cases. i change oil more than i should, but the tight-nasty trees (in the shade) is what we ride in summer months. the oil seems to hold up well in the warmer temps.

it only takes a few moments to have a significant amount of coolant overflow if your stopped or riding slow enough the motor overheats. The 1.1bar cap is a bit wimpy IMO for tight woods riding, but you simply can't stop. Even shutting the bike off is worse if it is real close to boil over, than to just keep moving (in my experience in the past 5 yrs of woods riding the crf450). I paid $20 for an "Outlaw" 1.6bar rad cap and that helps.. but won't prevent all boil overs. As those that know more than I have pointed out, running a higher psi cap than that could be trouble. I would throw the 13t front sprocket on if your in 1st gear a bunch. Not that it will have the bike rev any higher, but it may be a bit higher rpm when your at your slowest in the really tight stuff. As your speed picks up, can try the 14t front again..

Dunno, in my experience if the bike is close to overheating, shutting it off immediately starts to drop temperature. The coolant will begin to thermo-syphon, and you can feel the radiators rejecting a ton of heat. The TrailTech confirms it actualy. I was plowing through a deep mud-pit, and by the time I got out I was at 235*F. I shut it down immediately and within about 4-5 minutes it had dropped down to less than 200*F.

3,000 rpm? these bikes are supposed to idle around 1600 rpm.....

3,000 rpm? these bikes are supposed to idle around 1600 rpm.....

.. the manual says change the piston at 15 or 20 hours too.. :thumbsup: Not saying it is for everyone, but for woods riding it can be a benefit.

so with your bike idling at 3 grand does it not creep a large amount?

so with your bike idling at 3 grand does it not creep a large amount?

im not sure what "creep" is.. If you mean while stopped in gear with the clutch pulled in, it "creeps".. no, i have no issue with that at all.

3,000 RPM is a lot. I ride in some trails where you can't go above 2200 RPM in 1st gear:banghead:

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