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F4i coolant issue WTF

T

timbanks

New member
Joined
Jun 13, 2010
Location
Pittsburg,Ca
Moto(s)
Honda CBR
Ok. 2001 Honda F4i 600
I bought the bike and it started over hearing weeks later blah blah blah
So here's the deal. I started out by adding coolant and topping of the over flow. Still over heated. Pulled the thermostats out all the together hoping for better flow and thinking the thermostats was no good. Still over heating. I then flushed the engine and radiator completely at every inlet an outlet making sure there was flow at every inlet and out through out the bike while carefully inspecting the radiator for flattened fins. Still over heating. Keep in mind Everytine I did these things I put in fresh brand new coolant 50/50. I then replaced the waterpump but still over heating. Them ordered all new hoses and put them in over the weekend Guess what. Still freaking over heating. I'm out of ideas. On a cold morning it will sometimes ride at 170 to 180. And on warm days it can reach up to 210 to 230 And the fan isn't kicking on till 230. I thought most bikes fan kicks on at 220. I'm completely out of ideas. Could the gauge be reading incorrectly? Or? I will be rewiring the fan to a switch to make it a constant on or turn it on when I want it on. But I don't see that making a world of difference or am I wrong and that it will make a difference? Need your help please. Thanks
 
Pressure tested? No. I forgot to mention but I did put in a brand new radiator cap with a 11PSI. Please explain presure testing to me. Thanks
 
The pressure cap is removed and a special cap put in it's place and then the system is put under pressure and you either check for obvious leaks, or you leave the system pressurized for a period of time to make sure that the pressure doesn't drop.

11 psi? Is that what your system is rated for?

The reason for pressure testing is that all modern cooling system are designed to run under some pressure. Water boils at a certain temperature based on elevation or barametric pressure. Since this is a bit too low for the job of cooling a modern engine, the system is designed to run under pressure. Raising the pressure also raises the boiling point of the water/coolant. Without that pressure, an otherwise perfectly healthy cooling system will not do its job.
 
Well said. Thank ÿõü. And the 11Psi is a lower psi than factory. The factory calls for 17-19. So mine in theory should open early
 
You need to put the cap back to stock, the Japanese knew what they were doing when they designed the thing ;)

Sounds like you need to... wait for it... pressure test the system and find your leak ;)
 
OP: You apparently do not understand the function of the various parts of your coolant system.

The thermostat opens and closes to allow more or less coolant flow. That changes due to coolant temperature and is totally unrelated to the pressure cap or the pressure in the system. One has nothing to do with the other.

The pressure cap is there to make sure that the pressure in the system reaches a sufficient level so that micro boiling doesn't occur on the walls of the cooling passages around the cylinders and in the head. If you do not have the proper pressure, you will overheat. Period. And whether or not you're running 0, 11, 16 or 20 psi, the thermostat will still open and close as it should.

Install the proper pressure cap.
 
yes put the proper cap on and re-install the thermostat.

Also 210 to 230 isn't really overheating.. I mean 230 is kinda pretty hot but not for sitting still at a stoplight for a long time. If the fan comes on at 230 and then it cools down to 210 then it's fine. If it gets to 230 while riding on the freeway that's pretty hot though.

If you want it to come on earlier I'm sure you can install a different fan switch or you can install a manual switch.

http://cbrforum.com/forum/how-mechanical-40/f4i-lower-temp-fan-switch-maybe-other-models-105389/

Also since this is CA try running straight water and water wetter or some other water additive.
 
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1. Removing the thermostat CAN (though not always will) lead to over-heating due to the water flowing too freely and not having enough time to absorb heat from the engine and dissipate it when passing through the radiator. Put a correct thermostat in there, let it do its job.

2. Put the correct radiator cap with the correct pressure rating on the thing.

3. My F4i runs all day every day in the 180-200 deg F mark while I have air flowing, aka traveling at a speed that produces a bit of air through the radiator. If I'm in stop-and-go traffic without the option to lane split, or putting around town on a hot day it will creep up to the 220-230 mark. My fan comes on at about 225-230. Sounds like yours is doing the same thing and is operating correctly.

Water boils at 212 deg. F. For every 1 PSI you add to the system, the boiling temperature raises ~3 deg. So with a 10lb cap, you have raised your boiling temperature to 242 deg. I don't recall what PSI cap it should have, but it's probably in the 15 PSI range, so by dropping your cap to 11 PSI you've lost 12 degrees of heat before your water starts boiling.

If you're super concerned about it, stop running coolant (since it does little to help cool the engine and is mostly there to protect as anti-freeze) run a distilled water mixed properly with "Water Wetter" or other brand solution to help the cooling.
 
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66nick said:
1. Removing the thermostat CAN (though not always will) lead to over-heating due to the water flowing too freely and not having enough time to absorb heat from the engine and dissipate it when passing through the radiator. Put a correct thermostat in there, let it do its job.
Click to expand...

Removing the thermostat from the loop causes low operating temperatures, not higher. The cooling system runs wide open as soon as the engine starts, so it never gets to operating temperature because of the overcooling.
 
ALANRIDER7 said:
Removing the thermostat from the loop causes low operating temperatures, not higher. The cooling system runs wide open as soon as the engine starts, so it never gets to operating temperature because of the overcooling.
Click to expand...

I said can, because I've seen it happen with cars. Yes, a great majority of the time it leads to too much cooling, but it can occasionally lead to too much water flow, which doesn't allow enough time for the water to absorb and dissipate the heat.

Also, running TOO cool will lead to poor gas mileage because the ECM sees low engine temp and pumps extra fuel.
 
While you're in there fiddling around, check the overflow hose where it connects to the fitting just below the pressure cap. It MUST be free of cracks, holes and corrosion and also must be compliant, not hard from age and heat. Remove the hose from the nipple it fits on and thoroughly clean the nipple it fits on. (Steel wool works good.) When you reattach the hose, ONLY use a spring clamp. No screw clamps.

This is a commonly overlooked but nevertheless vital part of the cooling systems. ANY leak here can easily lead to the introduction of air into the main part of the cooling system and subsequent overheating.
 
ST Guy said:
While you're in there fiddling around, check the overflow hose where it connects to the fitting just below the pressure cap. It MUST be free of cracks, holes and corrosion and also must be compliant, not hard from age and heat. Remove the hose from the nipple it fits on and thoroughly clean the nipple it fits on. (Steel wool works good.) When you reattach the hose, ONLY use a spring clamp. No screw clamps.

This is a commonly overlooked but nevertheless vital part of the cooling systems. ANY leak here can easily lead to the introduction of air into the main part of the cooling system and subsequent overheating.
Click to expand...



Thanks. I did that already and also replaced the hose along with all other hoses. I'm going with thermostat and new 16-20 psi radiator cap
 
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