Bought a 2011 300 Raga a couple of weeks back, first ride this weekend bike rides nice lap 2 started overheating stopped and went home disappointed. Just checking through possible causes, hard wired fan - it's working ok, bike warmed up both pipes from water pump roughly same temp - pump appears to be ok, took thermostat switch out put in boiling water and continuity checked - ok.

Sort of worked through the immediately obvious culprits but they seem ok, anyone out there with any other ideas oh also when warmed up sounds a bit rattley (not a proper word but I'm sure you get the idea).

Any suggestions appreciated

Need better gas? Jetted lean? Seal or gasket leaking somewhere? Float bowl clean? Fuel flow ok? Gas cap breathing ok? Vents in carb body open? These ideas might help.Best of luck[or skill].

was the fan working when over heating does fan work when bridging stat connectors when running ,is fan running correct direction is external of radiator reasonably clean (can air get through it ok ) as above running lean rear brake sticking head seals failing colour of plug could determin coolant getting into cylinder ,if the seals have gone you might get petrol smell or oil in the radiator ,, ive seen a cdi go bad on a late sherco causing bad timing and erattic spark resulting in over heating

I've heard of this happening on Raga's - the oil way in the crank bearing on the transmission side is a hole drilled through the bearing that lines up with a hole in the casing. The Mag casing can expand a bit too much and the bearing turns thus cutting off the oil supply - bearing seal fails - fully or partially, and the resulting mess is burning lube, a real weak mixture and bl*****dy hot engine.

This problem happened to mine when the oil way in the bearing was blocked by a bit of swarf.

Also you could check that the ignition stator hasn't moved thus altering the timing.

good luck with the 'hunt'.

Paul Mac

Paul Mac

Does the fan come in when riding ? The thermostat should work before boling point as naturally its too late when boiling point is reached. Mine failed and did simliar issue.

If that test ok then remove pipe to rad bottom make sure the pump sprays out water by runing bike.

Remove rad and ensure water can pass freely. All so does the rad cap work as this should allow any excess pressure to release as an over pressured system will turn into a pressure cooker.

Rattling as it overheats normally happens along with a smell and its time to stop the motor.

Good Luck