pros and cons of not running a fan

[WB450r]

im in the middle of putting my quad back together from this years rebuild and was thinkin bout not using the fan..is the fan really needed??and how many of u guys dont use it??

thanks..

[bansheemorphine]

I don't run one because i have the crf flywheel, so really i can't. The only time i have it over heat is on real hot days right after a race when i am idling through the pits. Why do you want to take it off?

[Rich250RRacer]

Originally posted by bansheemorphine
I don't run one because i have the crf flywheel, so really i can't. The only time i have it over heat is on real hot days right after a race when i am idling through the pits. Why do you want to take it off?

Take the thermostat out, that will eliminate the over-heating when idling around and almost every other time.

[WB450r]

Originally posted by bansheemorphine
I don't run one because i have the crf flywheel, so really i can't. The only time i have it over heat is on real hot days right after a race when i am idling through the pits. Why do you want to take it off?

im taking everything off that isnt needed and to make my quad more simple

[d3ktrix]

Originally posted by Rich250RRacer
Take the thermostat out, that will eliminate the over-heating when idling around and almost every other time.

No it won't.
The thermostat fully opens at 203F.
The thermostat fully open and no thermostat at all will yield the same max temp.
Max temp is up to the radiator and the air flowing through it.

The bike will just run below optimal temperate the rest of the time if used in cold climates and cause premature wear.

[bansheemorphine]

Wouldn't removing the thermostat let the coolant flow better and in turn make it run cooler?

[Scro]

Originally posted by bansheemorphine
Wouldn't removing the thermostat let the coolant flow better and in turn make it run cooler?

Yes, but like stated before, it won't allow the bike to reach operating temperatures in certain climates. It may be alright in 90+ temps in the desert, but when it's 30-40 degrees, the coolant won't allow the motor to heat up properly.

[Rich250RRacer]

Originally posted by d3ktrix
No it won't.
The thermostat fully opens at 203F.
The thermostat fully open and no thermostat at all will yield the same max temp.
Max temp is up to the radiator and the air flowing through it.

The bike will just run below optimal temperate the rest of the time if used in cold climates and cause premature wear.

Then don't ride it in the cold. My 250R's seem to run fine and reach proper temp, even in the cold and there's no stat on them. My 450R has run fine and not had any overheating or premature wear issues since I took it out. Hell, Mark Baldwin even recommends removing them, no real need for it.

[eastside 400]

sometimes removing the thermostat will actually make it run hotter because the coolant flows so fast that it doesnt cool down enough radiator, if baldwin says to take it out then i would listen to him, they have em figured out. i know on other stuff though, if you dont want the thermostat part you just gut it out but leave the actual thermostat in so the system has restriction.

[Bradracer18]

From what I gathered is you can remove them because the part of the engine that you are wanting to cool down (head/cylinder) is directly behind the radiator. So, the fan really restricts air flow through the radiator, and it also doesn't allow air to hit the most vital part of the engine that needs cooled. If that makes any sense.....

[d3ktrix]

Originally posted by Rich250RRacer
Then don't ride it in the cold.


Good argument =)



Originally posted by bansheemorphine
Wouldn't removing the thermostat let the coolant flow better and in turn make it run cooler?

No doubt removing the thermostat could increase coolant flow rate. Also depends on how restrictive the rest of the loop is.
But when the bike is moving, IMO the stock radiator and flow rate is MORE then enough to keep these engines in the safe range. Even my engine that is putting out approx 60HP never goes over 185F when I'm moving good on the MX track WOT all day.

The only time the heat becomes comes an issue is when idling or at extremely low speeds when the fan is removed. Which at this point, if there is no/low air flow removing heat from the radiator, your coolant flow rate is completely irrelevant.

So sure, by removing the thermostat you could slightly increase the flow rate of the coolant, it might cut off a few degree's when you are moving fast and getting good air flow through the radiator. But is ur bike anywhere near leaving the safe range with it in? Doubt it unless you have other problems.

IMO there is more advantages for leaving it in. Your bike will warm up faster, keeping the engine in a more controlled temp range makes the most power and the most consistent fuel mixture. The faster the bike warms up, the faster everything comes into spec and runs optimal.

My opinion on removing the fan is as long as you keep an eye on your temps while it is warming up and idling and don't ride in any slow stuff it's pretty pointless.
At least in my experience my fan never came on under normal pace riding. But I also don't ride in 110F desert weather in soft sand like some ppl.

I just keep mine on as cheap insurance.
I don't really see any benefits to removing it besides weight and looks.

[Sjorge450R]

Pros: Weight

Cons: Too many problems to compensate for the 5lb weight loss.

[Ruf Racing]

Originally posted by Sjorge300EX
Pros: Weight

Cons: Too many problems to compensate for the 5lb weight loss.

^^ Agreed ^^ Too many people believe they have engineering degrees! :ermm: The Honda engineers must be full if **** putting extra inessential weight on these bikes. :rolleyes:

[Bradracer18]

haha, I do have an engineering degree.....

But, with that said... I think its needed for slower conditions, especially sand.


My fan is removed (bought it that way) and I'm going to put it back on. What is the process for doing this? The fan has a wiring harness/plug on it...but I doubt that is still on my quad. I know one goes to the thermostat, but where does the other go? The bike is a kicker BTW. Can it go to the same place my tether cord goes?

[brilo_pad]

I recently took my fan off and found washing the radiator a much easier task now that it is removed. Not that it was hard before-hand but now that it is removed cleaning the radiator is a peice of cake. I just thought that was a useful plus for not running the fan.

On the other hand, I think if ur serious about racing your 450r then removing the fan would deff be something to consider. I mean if it doesnt get used then no need for it to be there. I guess it depends on how u look at it. Im kinda a bare essentials person and appreciate the saying less is more :) But some people may feel having it there as a safe bet prob isnt a bad idea. Like i said its how u feel about it i think..

The thermostats another thing similar to that. Many bikes dont run thermostats. The CRF450 doesnt run a thermostat and it runs fine in more or less the same conditions as ur TRX would be running in. I guess again its how u look at it. I dont no to much about the thermostats, but for me i just took it right out, the way i look at it is its one less thing that can fail an cause a problem.

Everyone has there own opinions on something like this i think..
I guess i just wanted to share mine.

[Sjorge450R]

Oh I am also bare essentials kinda person, but the plastic fan being there doesnt really bother me. I would rather it be there and come off if ever need (sitting covered in mudding idling in a bottleneck) rather than warping my head in that same situation. IDK, its personal pref, but I feel like thats one thing not to mess with.

[brilo_pad]

yeah there is many situations were a fan could come in real handy an i guess for all it is, it is easy just to leave it on.

But for me i only race MX and so never really come into a situation were it will be of benefit to me. Well so far thats my general senses.
The reduced weight (even if it is only 5lbs.), less wiring, and cleaner less cluttered look is more appealing to me now when not running the fan and for that reason i dont run one.
But i totally agree everyones gonna be different on this one.