Over heating

[deuce72]

I've installed a new water pump and installed the 1983 Honda Accord thermostat, and still overheats. The fan does turn on when it gets hot. Coolant was coming out of the overflow and I also could see it coming out of the bottom of the thermostat housing. O-ring bad??

 A good friend suggests that my radiator may be plugged. I'm pretty certain I bled all the air out during the refill of coolant. Are there any other possibilities?

Thanks!

[Jim __]

Did you burp the water pump while refilling?  There is a bolt on the water pump at about 11 o'clock (facing the pump).  With the bike on the center stand and the radiator cap off, loosen the bolt until antifreeze comes out and re-tighten.  Refill the radiator.  Put the bike on the side stand and leave the cap off.  Start the bike.  Wait until the thermostat to radiator filler neck hose become hot thermostat opens.  You can feel it under the tank or just feel the radiator by the fill neck.  Refill as necessary and replace the cap.

What year is the bike?
Leaking o-ring is not good.  Needs to be fixed.
What does your temp gauge indicate?  I know it's not accurate, but most are consistently inaccurate.
Are the rubber seals in the radiator cap in good condition?
What did the liquid in the cooling system look like before you drained it?

[Daytona_Mike]

All of the above

Normal procedure says   that anytime you change the thermostat a new 'O' ring  should be installed. The old  'O' rings tend to turn into goo. If it leaks the cooling system cannot pressurize and the bike will always run hot. 

You can feel  a plugged radiator     (kinda hard on a motorcycle to feel-- you need an infra red meter http://tinyurl.com/y99udsbr)   .
The bottom gets full of sediment and  stays cool. I have seen this on old cars and trucks but not a C10.
I have seen radiator caps go bad because the spring gets weak and cannot hold pressure and boils over   even before the fan comes on.
Sounds like what you have.
Also you need to test the radiator fan  switch. (not the temp gauge sensor) I tested mine in boiling water  like this video.  You can test the fan first by bypassing the fan switch to make sure the fan  works. The fan switch does go bad on our C10's due to age.
https://www.youtube.com/watch?v=lkwJoLBGr9Q

What was the temperature gauge showing when it boiled over?

[Summit670]

Fan turns on when hot, but how hot does it need to be?   If the fan doesnt turn on until the temp needle is nearly in the red isnt turning on soon enough. 

[Daytona_Mike]

Yeah.. that would mean the fan switch is not good. They normally turn on half way

[Jim __]

Where does/did the temp gauge normally sit while cruising down the road?

[deuce72]

When cruising down the highway, needle reads just past 1/4. Would not start to heat up until "city" like driving. I get it home and starts to puke when needle is just past halfway.  I bought the log orings along with the thermostat oring of course. I may track down a radiator cap as well. Also, decided to give the radiator a flush.

To answer the bike year, it is a 98 and I've got 52,xxx on the clock.

Jim I'm pretty certain I burped the system. I also burped up by the thermostat. The coolant was fresh from the water pump install.

Thanks for all the help!

[deuce72]

I forgot to ask, where is the radiator fan switch located?

Thanks again!

[Jim __]

Fan switch is on the lower left side of the radiator (No.1 in the pic).  It has a 2-wire connector.  You can short those 2 wires together to verify your fan is working.  If not, check the fuse in the J-Box.  Caution, the power to the fan switch is always on regardless of key position.  Also, check you fan blades for signs of melting or distortion.

[deuce72]

Thermostat orings and 2 coolant log orings installed. Still seems to run hotter than what I'm used to seeing on the temp gauge.

Where do you guys see your temp needle sitting normally during highway and mixed riding? Just curious.

Thanks

[Summit670]

1/3 to 1/2 is my normal range.  One time on a trip to CO I noticed it going 3/4 or more in city traffic but as long as there was good airflow it cooled down.  Ended up being bad temp sending unit.  Forget the part numbers but there are aftermarket units for cars that fit perfectly, though the activation temp is like 5-10 degrees cooler.   

[Daytona_Mike]

I installed a manual switch when  was running hot in stop and go traffic..(it was a bad O ring thermostat gasket) and I would turn the fan on before I got into traffic when the needle was still down at 1/3 level.
It came in handy but after fixing the problem I never had to use the switch anymore   

[Jim __]

Do a google search on "Common Concours Part Numbers".  That will give you the .pdf with all the maw Kaw and substitute items you can use including fan switches and radiator caps.  I carry a copy of this on all trips.  See the attached for testing the temp sensor and fan switch.  Just be sure you don't put both of your leads into the water while testing at the same time (could effect readings).  There's an 18 degree range for "fan on" and it's located on the outlet (cool side) of the radiator so you'll probably get a wide range answers.  If you leave your radiator cap on, you might get away with not draining the coolant system if you can find a cork or rubber plug to put in the hole if you pull the fan switch to test.

Have you done the "free power mod"?