I have an 08 R6. The bike is overheating and not cooling down! The temp gets to 212 and the fans go on but the temp continues to climb all the way to 240+. I have flushed the radiator and refilled with water but no help. I checked the thermostat and it is good. Installed new radiator cap. Drained oil, looks normal. The bike runs great with no significant loss of power. Why is this bike not cooling down? What else should I be looking at? I'm fearing a head gasket but figure I would see symptoms.
Does your R6 have the rubber tube capped off down by the water pump? Some racebikes do and you need to bleed the air out there as well?
there's a little clear plastic 90deg elbow on the top of the overflow bottle. Look at that elbow when you start the bike (will need to have the bodywork off ideally). if it starts to bubble into that elbow pretty early on during warm up, it's likely a head gasket. I just went through this with my bike last weekend. Spare sb motor, never an issue in 6 YEARS of using it as a back up from time to time. Had it rebuilt.. somehow the head had a 2-thous imperfection that for some reason sealed before. (so JUST replacing gasket will not solve my issue, head needs resurfaced). My bike never ran above 190F on track before, with 2 different motors, but was 200F pretty quick, we tried a new cap but it pushed bubbles into the overflow, and you could SEE little bubbles in the fill area with cap removed. Combustion is pushing past gasket and displacing coolant (in my case). Check this way first as it's super easy.... from there, may want to put on the dyno and see if you are lean for some reason now. Also.. are you seeing any coolant spatter on the MUFFLER ? clear indication water pump seal is failing OR it's pushing enough coolant to overflow the overflow bottle. We did another test when home and motor out, put 80psi for 10min on each cylinder, and a finger tip of a rubber glove attached to the front coolant spout.. on cyl 2, it would leak enough air, even at 80psi, to fill the finger tip up and start to balloon it . Measured head and found small imperfection with blue gunk he uses to check..
I've had some of the paint/coating that is over spray inside the inlet of the radiator flake off and partially clog the radiator but you said that you flushed it. Another simple thing was the overflow hose was folded inside the bottle so the water would push out when it was hot but not get drawn back in when the bike cooled down causing the level to be low the next time out.
when u remove the cap after some overheating, is it filthy? if theres lots of crap on it, its probably not sealing even though its new. my 08 has this issue now because I haven't been flushing the Water Wetter often enough. im replacing the beat up radiator and hoses because its a race bike and im tired of looking at them.
I have seen cars and trucks with those symptoms and it turned out to be a faulty water pump. One had the blades corroded off the impeller and another had no impeller at all (I never figured out what happened to that impeller.)
How do I know if the water pump is moving water? I pulled the pump. The impeller moves freely and blades are all intact, but how do I know its actually spinning when the bike is on? Also, new problem after removing the thermostat. Small developed after reinstalling it. I see there is no gasket for the cover. Is it ok to use a silicone sealant to make a gasket? I need this running in 18 days! I doubt I have time to remove motor and get it to someone to fix if teh motor needs to be out.
also... if this is a race bike, remove the fans. they arent helping with temp on track. but that likely wont solve your problem.
If the radiator gets hot all over (not just in spots) then the pump is moving water. I don't think your R6 is capable of thermosiphoning.
If you have a blown head gasket, sometimes you can see bubbling in the cooling system when you remove the cap, while the engine is running. Also, they make pressure testers so you can pressurize your cooling system and see if it holds pressure or looses pressure from a blown head gasket, or small leak somewhere else.
there is no "gasket" for your T-stat. rubber seal that is around the t-stat housing. It's round. That's it. You are making more work for yourself... as i stated earlier, simply remove the cap, start the bike. If you see bubbles, even a few, you-be-fucked and head gasket is very likely leaking combustion gas. There is almost zero possibility your water pump shaft is broken. There is a tongue just inside that the grove of the water pump shaft slides onto. It's that simple. If you don't line these 2 parts up, you won't be able to push the wp into the motor. Once the t-stat is open, you will see coolant flowing in the open neck of the radiator. Problem is to get it this hot, ya need to have the coolant level quite low or it will pour out on the floor as it warms up.. I would leave your fans ON if you haven't removed them. Your bike should have no problem cooling on track with them in place, and it will be a benefit when you are sitting on the grid waiting for some dumbass to be told where his spot is when he forgets to get the grid spot ahead of time and didn't write it on some tape and stick to his gas tank... or there's just a long delay for some reason. I don't have em on my bikes, but there are times i wish i had at least one
there's a kit you can buy that tests for hydrocarbons in the coolant so you know if the gaskets are blown. I've seen them sold online and at pepboys. https://www.amazon.com/Lisle-75500-Combustion-Leak-Detector/dp/B0007ZDRUI this is a better kit but 2 times more cost, https://www.amazon.com/UView-560000-Combustion-Leak-Tester/dp/B000NPDL76
so how bout a bad radiator? Never really had a radiator just fail(without damage)but I guess anything is possible. But really how? As long as its not blocked and water is flowing, right?
Radiators are fairly basic in design. They’re meant to have the hot water flowing against the surface area that’s getting cooling air on it, thereby exchanging heat. As long as it’s flowing water this heat exchange process is working.
What Melka said bubbles first. If your rad has a lot of even slightly bent fins it may not flow enough air, a screwdriver is a cheap fix to straighten them all out but they do make combs that do the same thing quicker.
You are seeing symptoms, all of them. Sounds like your seeing the early stages of it, next is pumping coolant all over the ground if it gets worse. I had one on a diesel truck one time, never suspected it being a head gasket and i had it running for like 8 minutes from dead cold. As you know it takes a diesel a bit to warm up, and it was nowhere near being warm (like less than 100*). I pulled the cap off and it blew that fucker out of my hand like a shotgun went off!
