OVERHEATING! Help to diagnose 2011 ABS
I am a bit perplexed about what is happening with my 2011. I was hoping one of you nows a lot more about this than I do and could possibly help me figure this out. Here are the details:
The bike ran a bit hot during late August/September (thats when i got the bike). It would normally run in 220+ range (even after the fan kicked in). I've had 4 other zx10rs and i thought that all of the previous ones ran a bit cooler. So anyway. I was riding a week ago in a 65-70 degree weather and as i came to a stop at an intersection i saw the temperature start to rise past 230. It got to 235 and then i looked down to the right side of the bike and noticed vigorous bubbles coming out into the overflow coolant tank to the point that it started bubbling over and i started dumping coolant on the pavement. I immediately turned of the bike and let it cool down and parked it. I lost about 1/2 quart of coolant in that incident. So i went and got more coolant and topped off the radiator (it was 50/50 premixed). Started the bike --> no bubbling anymore and the temp does not get over 203-205 while standing. A few days latex i start seeing the temp go higher to 215 or so. The temperature now is very unpredictable - the temp goes up for seemingly no reason ( i.e. i would not predict the temp to get to that point based on the riding, airflow and RPM). I think there is something going on still.
Things I've done:
-sprayed down the radiator on the outside with a brake cleaned to make sure the fins let air thru (helped a little i suppose).
- When i put my hand on the thick rubber coolant hose on each side of the bike and rev the engine --> i feel the pressure build --> so i think the pump is pumping ( at least a little).
-i don't see any leaks under the bike when i park it, but immediately after seat of the bike (after its been sitting for a day or more) i think i smell coolant burn by the radiator/header area. ( I THINK).
What do you guys think may be a problem? How can you explain the symptoms? I was doing a bit of research and there was mention of blown head gasket (when you see bubbling). But i would imagine that you would be bubbling all the time. But ever since i topped off the radiator, there hasn't been any bubbling happening in the reservoir (there would be bubbles, i think, if its constantly blowing exhaust into the coolant system).
Could it be that the slight leak in the system sucked in enough air to cause it to expand enough to bubble over? Or maybe there has been water in the system? (but it looked greenish). Or maybe its the bad thermostat is what causing the variable temps...
Help me out guys!