i turned on my bike this morning and put the choke on al the way and i left to go inside for a bike while it heated up then i came back out and the bike was smoking up a storm and leaking a lake of antifreeze. i went to the honda dealership today and they told me that it probably a head gasket or a fried piston. when i turn on the bike and let it sit for a while and it goes way over the hotest point on the temp gauge. anyone have this problem before? if so what are the characteristics of a fried piston b.c that scares me the most.

 

I gotta ask.. does your fan work??

 

yup i have a switch for it

 

How does it run? Have you performed a compression test or a leakdown test on the engine? Have you performed a cooling system pressure test? I suppose the average weekend mechanic wouldn't have these tools, but you can pick them up at Harbor Freight pretty cheap, or you might be able to rent them from Autozone. The first thing I would do is perform a cooling system pressure test. It will pressurize the cooling system, with the engine off, allowing you to see where the coolant is leaking from. Have you checked your oil to see if it's milky? If it is, that's an almost definite head gasket. I'm not sure how you "fry" a piston. I'm a mechanic and I've never heard of that unless you burn it with lean fuel condition when running nitrous. If your bike overheated, you may have some serious issues. The engines are aluminum, as well as the pistons, and once they overheat, they usually warp which will require some machining. Do yourself a favor and don't take your bike to the dealership yet. Stick around on here, and we'll try to help you figure it out.

 

i checked the oil looks good to go. flush the antifreeze water pump and resevor. checked spark plugs and they are still good cleaned them up a little bit. leaking has stoped but still overheats on the gauge. took off the radiator cap after running it and wasnt boiling so i was told it probably isnt my headgaskets.

 

Ok, well, leaks don't just go away. Get a cooling system pressure tester and test out your cooling system. You'll find the source of that leak. But, I just thought of something since this happened to me at work today. I was working on a Toyota forklift (That's what I do) I was running the truck, letting it get hot, checking for leaks. In the meantime, I started working on another truck while the other was running. I came back 20 mins later to find the temp gauge pegged out, and an infrared temp reading showed the aluminum cylinder head to be 255 degrees!! The radiator cap had blown due to its pressure rating, and the radiator was overflowing with coolant. I checked everything, added coolant, and BLED THE COOLING SYSTEM. It ran fine with no overheating problems after that. On our bikes, take off the radiator cap, and let the engine run for about 10-15 minutes. This bleeds all of the air out of the cooling system, eliminating air pockets that will make your bike overheat. Also, take a look at your radiator cap, and make sure the rubber seal inside is intact. But I can't emphasize enough the importance of pressure testing your cooling system. That's the ONLY way you're going to be able to accurately find a coolant leak. Now, for the cause of your overheating, try this; Remove your thermostat housing, and take the thermostat out. Run your bike for a while like you normally do when it overheats. If it doesn't overheat with your thermostat out, then you likely have a bad thermostat. You can also drop the thermostat into a pot of boiling water and watch to see if it opens. If it doesn't open, replace the thermostat. I know they're expensive at $50, but you really can't go without one, and NEVER run your bike without a thermostat for a period of time longer than the test I mentioned above. Good luck, let us know what you find.

 

i fixed the bikes overheating problem for a while,i got a new waterpump, checked my thermostat and i dont have one and i called the local honda bike shop and they said that was fine. then i fully flushed the colant. but i ran into another problem the radiator had a little whole that leaked out off. took it off and going to send it to a local welding shop to fix it up. so everything is good exept the radiator now. o yeah and i lost my cap for the resivor for the collant anyone have an extra one i could get its the little rubber one thanks

 

My bike runs hot going thru town or slow, under 25 or so. Since I changed the antifreeze last year and then put some silicate free stuff in this Sept. After reading the replies I'll take the radiator cap off and let it run a bit then change the thermostat if that doesn't work. It took 2 quarts of that expensive premixed stuff then part of a 3rd one for the reservoir. What a pain to take the radiator cap off, then there is the stuff to remove to get to the thermostat. I'm assuming it is on the left side.

Just the info I needed to know. Thanks.

 

The radiator cap is on the right side. It's NOT ok to run your bike without a thermostat. If you run an engine colder than around 170-180 degrees for an extended period of time, excessive wear occurs. The same goes if the engine temperature goes above about 215 degrees for an extended period of time. The thermostat stays closed, keeping the coolant from circulating through the radiator, allowing the engine to warm up. Removing the thermostat is a big mistake, and you'll regret it in the long run. Yes, they're $50, but it's cheap insurance if you want your CBR to last for a while.