My buddy and I rode this evening, and his 650 was hot and we could smell antifreeze. It was coming out of what I think is a vent line, the owners manual was no help. I could not see any on the level indicator. We filled the reservoir, and it did not seem like the water was circulating. should it circulate when the motor is running, does it have a thermostat? need help. Thanks.

 

There is a thermostat just like a car. It is located in the same housing thingy as the radiator cap behind that little cover in front of the handle bars. Thermostat problems are rare, but they have happened. I don't know what vent you are talking about. There is a water pump leak tube under the block by the oil drain. there is a coolant bottle overflow. Overheating could cause water to exit the bottle overflow. There shouldn't be water coming out of anywhere else.

The water doesn't flow much at idle, you may not have seen it moving. Hit the gas and it swishes around. It is almost not possible for the water pump to not pump, unless clogged or dry.

Most overheats are caused by a clogged radiator. It must bne well cleaned after each muddy ride.

The stock 650s run lean in many cases. Lean causes overheating.
The stock CDI retards timing. Retarded timing causes extra heat. The diamond G cdi will help this.
The head pipe heats the radiator, thermal wrap on a part of the exhaust coming from the front head will help with heat.
Water wetter may help (or other coolant additive).
50/50 coolant/water cools more effectively than 60/40 coolant/water. Water carries heat better, but you can't go straight water.

 

Nyroc, the water is probably coming from the overflow. The radiator was very dirty. What is the best way to drain the radiator, where is the drain located?

 

Take off the bottle, and you will see the drain (a bolt) in the water pump housing. That drains the whole system.

You have to do a really good job cleaning the radiator (outside) or you will overheat fast. I use a garden hose with a non adjustable nozzle, and I poke it inside the grill holes/slots and spray around.

USe a pressure washer, but don't spray too close (don't spray from the back.

If the rad gets muddy, don't ever let it sit then ride again, because the mud gets even harder to get out.

 

The best way to clean your rad is to find a nice clean flowing river, about 2 feet deep and run your P650 up and down. It will clean that rad good and the rest of your bike as well. I do that to all my quads after I go on a trip, helps the cleaning process alot!

 

On Highlifter.com you can buy a 12volt portable compact pressure sprayer to clean that radiator
while out on the trail also. It has a double filter screen on it and a tube you can put into a clean stream,lake,undisturbed water hole etc.

 

I have had my bike overheat on one occasion, and have seen almost every Prairie that I have ridden with in the hot summer months experience the same thing....until I realized what I am about to say:

The radiator collects and holds an AMAZING amount of mud and crud when following behind someone on a wet trail. When washing the bike, don't forget the radiator! Using a hose, a power washer, or whatever, direct the blast through the grill and LET THE WATER RUN UNTIL CLEAR! This might take several minutes! Ever since I started doing this not only has it not overheated, but I notice that the cooling fan doesn't come on near as much as other Prairies who I am riding with. It makes all the difference in the world!