my dads grizzly runs too hot and overheats when it shouldn't. what is the problem

 

How do you know its overheating?
First thing is check the coolant level. Next check to be sure the radiator isnt plugged up with dirt or mud, which is a common reason for overheating.

 

What year is it? Does it have the louvered side panels? Is the fan working? Is the light coming on or is it just running hot? More info needed.

 

More info!

 

it is an 02 model with the 04 vented side panels, coolent level is fine radiator is presurewashed clean. the temp lite comes on when driving under normal riding conditions, not meaning fast or hard on the gas

 

700r,

Your Grizz is probably not actually overheating. You most likely have a bad #1 thermal switch. It's located by your water pump and will cost about $30.00 and about 20 minutes to replace it. My 04 Grizz had the same problem. I changed out the faullty sending unit (thermal switch as Yamaha calls it) no more temp light.

Good luck [img]i/expressions/face-icon-small-smile.gif[/img]

 

the coolent boils in the radidador and leaks boiling coolent out the resivoir

 

be sure both sides of the radiator are clean!

 

If you're boiling over forget what I just said about the #1 thermal switch and go with the total radiator scrub routine. Make sure your not jetted too lean or running bad gas. Also make sure your cooling fan is coming on. Thats controlled by thermal switch #2, and look at your thermostate to see if it's sticking. Make sure your coolant is a 50/50 mix and not straight antifreez.

 

thank you the radidador is clean and the fan is on all the time.