HELP: 09 KX450F Turns off after about 15 minutes of running

Elbows wrote:

Have you tried a new spark plug? I know that may sound stupid but my 09 kx450 did the same thing but it only took about...

Have you tried a new spark plug? I know that may sound stupid but my 09 kx450 did the same thing but it only took about 5-10 minutes to shut off. I had a friend bring his to the track and we switched out everything including fuel pump, stator, coil etc. He finally said have you changed the plug and I said no because it would start firing again by the time I got it out and it had cooled off. Just a thought.

lostboy819 wrote:

That is being kind, he is in way over his head and he will just end up costing himself a lot of money, some people are...

That is being kind, he is in way over his head and he will just end up costing himself a lot of money, some people are not cut out to work on modern motocross bikes plain and simple. If you don't know what's in your radiator the you are one of those people.

bichwolf wrote:

Facts.

Jkawi wrote:

It's kind of funny when people post an issue asking for help and then only look for the answers they want to hear... To me, the...

It's kind of funny when people post an issue asking for help and then only look for the answers they want to hear... To me, the coolant coming out of the overflow speaks volumes as to why the bike is shutting down after 15 mins. Motor is probably filling with coolant. Or water. Or something... It's even more suspect if "the head gasket was just changed". Who did it? Were the bottom end and cylinder decked flat? Checked for cracks in cylinder and head? Is there smoke coming out the tailpipe? Is the base gasket sealing around the coolant ports? Coolant in oil? Oil in coolant? Pretty obvious stuff to look for but if you have no idea, then get someone who does before you fuck shit up.

Anthony_Horner wrote:

My 2009 KX450F will run fine for about 15 minutes before it shuts off. Once it shuts off I cannot start it back up immediately. I...

My 2009 KX450F will run fine for about 15 minutes before it shuts off. Once it shuts off I cannot start it back up immediately. I have to wait about 20 or so minutes (maybe to let it cool down?) to kick start it and it'll start right up. Along with this, I noticed when I rev the engine at a high RPM in neutral, the coolant overflow hose spews out coolant, or water... I'm not sure which.

I have read online that the cause could be many things, blown head gasket, bad radiator cap, or other things.... I recently had the head gasket replaced so I doubt it is that.

Will overheating cause the bike to turn off(stall) automatically? Any advice and information would be greatly appreciated.