[gobi42]

while my last tread sparked a interesting conv. with other members i have been on different forums and have seem posts about putting a switch on the fan relay to have the fans running all the time to keep the bike cool or reversing the fan direction. I aslo read about adding radiator shrouds to help direct air. My question is what is the best way to cool the rc down and keep it in optimal running temps. Now as far as optimal temps are consered i have heard any where from 160 to 170 is optimal.

 

[SubSailor]

Honda went from one fan attached to one radiator on the SP1, to a fan for each radiator on the SP2 for additional cooling.

As for myself, the previous owner had a puncture in the left radiator tank and rigged it using JB Weld, which didn't hold, much to my displeasure.
Also, one fan was developing squeaky bearings, so it made my list also.

Once I had the hole heliarc'd and pressure tested, I replaced both of my fan motors and inspected the whole system, made sure everything was nice and tight, then filled with coolant (Engine Ice pre-mix in my case).

Now I don't have all these mega high temps folks talk about.
In stop and go traffic, it will climb to 221 at most, but the fans cool it down to 205 in a few minutes. Once moving in town, it generally stays around 205 to 207.
But if moving at a decent pace it cools down to 187 no matter how fast I go.

When the fans run, they pull air from the outside in. When moving, the air moves from the inside out. That's why some reverse the fan motor connectors.

Also if the bike is old, the thermostat could be getting old and not working properly. Also the radiator cap may not be maintaining pressure.

Mine is an '02, so it's 7 years old. Things wear out, break, and need maintenance.

Such is life. But I like working on it. It's therapy to me.

 

[DRFLGD]

My RC51 seems to run about 187* or so when moving. It will climb up there fairly quick when in traffic. It's just the nature of the beast.
My CBR1000rr runs about 177* when moving.

 

[Gipper]

I reversed BOTH of my fans and put them on a switch. The key is to turn the fans on BEFORE the engine gets too hot. The fans push a lot of heat out the vents when at a stop, which could get uncomfortable (I read somewhere that Honda had the fans pull air in for rider comfort?).
The big plus is the fans don't work against the ram air when you get moving again - the engine cools down from 200 to 166 in about a minute.

Eric

 

[gobi42]

ok that's cool gripper how hard is it to put both of the fans on a switch?

 

[Gipper]

It's not "Gripper", it's "Gipper." Sheesh, that made me sound like I was hanging out at the elementary school in a raincoat waiting for the bell to ring...

It's easy. If I can do it, anybody can. All you have to do is find the relay in the tail - picture below (I hope). Cut the black wire with the gray rings and install a switch inline with the other end to a ground. When that wire is grounded, the fans come on.

http://img.photobucket.com/albums/v207/Axewielder/RC 51 Fan relay/DSC09050.jpg

 

[gobi42]

sorry gipper my bad thanks for the tip i'll try that; did you switch fan blades or did you just reverse the wires on the fans

 

[Gipper]

I just reversed the wires. It's very simple. You'll have to remove the side fairings (pain in the butt part). There is a connector mounted on the front of each radiator. Disconnect the connector and look at the pins - one side has a tab that locks it in place. You can use a small screwdriver to push the tab down and the wire will just slide right out. Then you swap their position in the connector - they just slide right in and snap into place.

Voila! The fans are reversed.

Eric

 

[gobi42]

Thanks for that i'll have to give that a try for sure