Running Hot

[BIG--T]

I posted before that mine may or may not be running hot because the stupid idiot light came on. After doing what most suggested I ordered a temp radiator cap.

 My fan does work and I changed the coolant yesterday (didn't really need it, looked good and 300* boil over protection) but looks like the PO already did it at l2k+ miles ago.
I drained and replaced coolant to the rim and several minutes it went down a little I added coolant and I bliped the throttle a few times. It idled around 25 minutes. I could see it circulating good but sometimes it would just come back outta the radiator and go back down. During the whole process Every time I gave it gas it would come out. Is this Normal?
In the old days I would take them out and of course winter time not much heater but ran real cool year round. So Do I even Need a thermostat? If so, does anyone have a cross reference for an auto parts store?

Thanks in advance!

[Bighead]

With it running with the cap off when you give it throttle (at running temp) the level should fall and then rise when you let off.

[rhinor61]

Big T.
My experience is ALWAYS run a thermostat, part of the process is to provide water flow restriction in the circuit.
2nd it keeps the engine temperature at the optimum set point for the best efficiency. Meaning too cold the engine would not be allowed to expand to designed temperatures.

I found this:

Thermostat
I found the thermostat that is the automotive application that Honda must use. It has 160, 180 and 190 degree. The part #143-0687 this is a car quest number the application I ordered was for a 93 Mitsubishi montero with a 3000 engine v6. Its a direct fit. I put the 180 in the Valk and it works great more power and feels allot better in riding because it doesn't throw as much heat out. This is the same temp as the stock Honda thermostat but the temp is consistently lower. I am going to go with the 160 for summer. I think a 94 supra takes the same too

Contributed by Robert

1981 Honda Civic has the same thermostat.

Motorad part numbers. They fit hundreds of cars.

O.E. Type Thermostat 240-160 160 degree. Alternate Temperature.
O.E. Type Thermostat 240-180 180 degree. O.E. Recommended Temperature.
O.E. Type Thermostat 240-192 192 degree. Alternate Temperature.
High Flow Thermostat 2040-160 160 degree. Alternate Temperature.
High Flow Thermostat 2040-180 180 degree. O.E. Recommended Temperature.
High Flow Thermostat 2040-192 192 degree. Alternate Temperature.
Fail Safe Thermostat 7240-160 160 degree. Alternate Temperature.
Fail Safe Thermostat 7240-180 180 degree. O.E. Recommended Temperature.
Fail Safe Thermostat 7240-192 192 degree. Alternate Temperature
 

Thermostat Gasket

Murry 2278 rubber seal from a 1990 Volvo Model 740 with a 2.3 DOHC engine

found at http://www.jkozloski.com/generic_parts.htm

yes the coolant level will go up and down with throttle position once all the air has escaped out.

Pulling your spark plugs will tell you if you have a cylinder running too hot or too cold, by comparing them.

A compression cylinder test will help determine a head gasket issue.. but look and compare your spark plug colors, insuring that they are compare to be the same color.

i hope this helps..

John
I hope this helps.

[BIG--T]

Thanks for the help and references. Mine is doing the exact opposite of what y'all are saying. After putting in fresh coolant it idled for about 30 minutes and when the coolant level first dropped I topped it off and blipped it a few times and bubbles come up. Periodically it would just run over at random and go back down. Every time I gave I revved it up out it came.

The plugs looks perfect. I will ride it in a little while and let it idle when I get home and see.

[WintrSol]

When I fill a radiator on a bike, I have the front wheel raised, like on a 2x4, to help any air rise to the radiator. Then, run it until the thermostat opens, to push those bubbles forward; you can feel when it opens, as the radiator begins to warm. Revving to see if the coolant rises or falls isn't necessary IMO. At this point, the coolant is warm, so I let it completely cool, and fill the radiator above the neck. Since we have a return system, I would then fill it slightly above the full mark, install the radiator cap, and run it until the fan comes on. Any air left should push out the radiator cap to the return bottle as the coolant expands. After the engine is cool, check the level in the return bottle, add if necessary.