CRF Getting Hot!

[KTMDan]

My 03' CRF gets hot and starts boiling over if I let it sit and idle too long. After about 5-8 minutes of just idling antifreeze starts running out of the overflow tube. Anyone else having this problem. First 4-stroke I ever own, is this normal?

 

[Rich Rohrich]

Race engines are not designed to sit and idle for 5-8 minutes. The cooling system is designed to be as small and light as possible so it gets hot fast if there isn't air moving through the radiators, not to mention idling is really hard on the valve train.

So yes it's normal, and it's best to avoid idling the engine for extended periods.

 

[KTMDan]

Thanks Rich! That makes sense and I was thinking the same thing. How long should I let it warm up for then. My old 2 stroke would take about 5 minutes to warm up. I this too long?

 

[Rich Rohrich]

These bikes warm up fairly quickly. Give it a minute or so and ride it easy for the first couple of minutes to give the piston and barrel a chance to expand properly.

 

[Boozer]

Originally posted by Rich Rohrich
not to mention idling is really hard on the valve train.

can you please tell me more about this?