Need Help, long read

Hi guys, hoping you guys can help me out with a problem I am having. To give you some background on the bike it is a 2005 TE 450 pretty much stock with a JD jet kit, uptite Y, and a few accessories here and there. It has a history of overheating in really tight woods.

A few months ago at an enduro I had some overheating problems in some very tight woods. I looked down to see radiator fluid all over my boot and fluid leaking out of the left front radiator and a small bend in the radiator. I let the bike cool and opened the radiator cap to add some water from my camelback. I was able to ride the bike back to the start about 1/2 a mile at a time and the bike would then stall out and run terrible (popping and very difficult to start), this continued for about 6 to 7 miles.

Winter came and I decided to put the bike in the basement and do some work to it. I tore off the bent radiator and shipped it to Myler's (they do great work) and had them straighten it. I got the radiator back and installed, installed a fan and bracket hooked up to a switch, replaced all the radiator hoses, added some engine ice, and even wrapped the header pipe with heat wrap.

This is where it gets interesting!!! Today I took the bike outside to test her out. I fired her up without an issues and everything seemed fine. After approximately 1 minute a steady amount of steam came from the right front radiator (This is not the one that had a leak). I thought maybe it was some spillage so I let it sit for a few moments to see if it would burn off. As the bike was steaming I figured I would take it for a spin around the block. Bike ran fine around the block but did notice steam still coming form the radiator.

Once I returned to the house I found the steam was still flowing from the radiator and I was getting fluid spraying out the overflow tank. The bike then began to run terrible, stalling, backfiring and very difficult to start. (This was only after 2 minutes of riding and maybe 3 minutes of total time sitting).

Any ideas what could be going on? My thoughts are maybe the water pump has failed, head gasket failed or maybe something else?

Thanks for your help in advance and I hope you can help me out.

Dave

Start the bike with the radiator cap off to see if you have flow. I had my water pump impeller nut come loose and consequently stop pumping. Take the housing off the water pump and have a look.
Could be some blockage in the line as well. May want to disconnect one of the lines and blow some water through the system.
Good luck.

What you are describing sounds like a cracked head or head gasket leak. If compression gets into the coolant, steam, boiling and all kinds of nasty stuff, including rough running can result.
If there is a compression leak, you should be able to see bubbles or bursts of steam, when the bike is running with the cap off.

Thanks guys, I'll begin the troubleshooting on the bike.

Yes, this happened to mine, ended up blowing out a head gasket due to it overheating when the impeller nut came off.

Update: Removed the radiator cap and everything seemed to be flowing fine. Also took off the pump cover to inspect and everything looked good there too.
It does look like the right radiator has a pin hole leak and this is why the radiator is continously steaming.
Still not sure why it is running rough when the bike gets warm. Will do some more inspecting and keep updated.

If it suffered severe overheating I suggest you drain the oil and inspected the two oil strainer screens, looking specifically for any black pieces of plastic. If found, you better pull the ignition stator cover off, looking for damage to the coils.

My '07 450 overheated after radiator damage ... found the screens loaded with black stuff..... pieces of insulation from the stator coils. Bike wouldn't run..hard starting and backfiring .... ignition failure.

Not saying that's definitely your issue, but might look there. BTW, my bike didn't blow it's head gasket as a result.

I now have armor surrounding my radiators and a fan too.

dave

Well did some more work on it after work. Repaired the radiator and got rid of the steaming issue, changed the oil and everything appeared to be normal. I also changed the plug and emptied all the radiator fluid and installed new engine ice and water wetter.

The bike seems to be running much better but it is still heating up very quickly. I let the bike sit at idle for approximately 2 to 4 (Was never an issue before) minutes and the bike gets extremely HOT. So hot that you can hear the radiator fluid making boiling noises trough the hoses. I just can't figure out what the problem is. It has an uptite Y, water pump is working fine, running better coolant than usual and all radiator issues have been repaired. The jetting seems to be perfect according to the plug appearance and I have no other thoughts on what it could be.

Any thoughts or ideas?
Thanks,
Dave

Sounds like you'd better do a leakdown test on it before you really do some damage. Only takes about 15 min. any decent shop should be able to do it. Then you will know if you have a head or gasket problem.
It will pressurize the combustion chamber, if there is a leak it will also pressurize the cooling system.