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Air Cooled bike with a fan???

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Okay guys...I've searched for something similar, but nothing. If I accidentally duplicate it...tough. I understand that air cooled bikes need a constant stream of air to work at the correct operating temp, but what if you ride tight, technical trails with a big thumper, and its 100+ degrees outside? After the little scare I had concerning my oil temp (actually fried an egg on my crankcase...lol), I was wondering about this...what if you could wire up a 12V fan to the side of your cylinder that kicks in when your oil temp rises above a certain temperature? Or for simplicity's sake, even a handlebar mounted switch that you could turn on when you feel it's getting too hot down there? My bike doesn't have a oil cooler, and I'm feeling quite sorry for it on those hot days. Any advice/guidelines/cussing would be appreciated.:)

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harley daivdson makes a fan kit for there bikes and there'll air cooled. im

sure you could make something up using an old computer fan, i would just use a toggle switch it would be alot easier then trying to find the right oil temp sending unit.

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Back in the 80's, DG used to make an air scoop that mounted on one side of the engine to help cool it. This was on 2 stroke engines before everyone went to watercooling. I believe the last air cooled Honda CR480 came from the factory with one.

One a 4 stroke, I think the best thing to do would be to mount an oil cooler or a larger one if you already have one and run synthetic oil.

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Thats great guys...only problem is that the 550's didn't come out with oil coolers. I've thought about installing one, but I wouldn't know where to put it. I'm currently running diesel motor oil in my bike (blame my dad, he bought that crap bulk), I think it's a 20W40, but I could be wrong. Not fully synthetic though. A pc fan would look weird on a bike...I have an old one with those colored LED's on, maybe I'll put that one on...

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You will have a hard time making a computer fan cool things much, unless it is a big azz fan (or a lot of them). As several others suggested, run an oil cooler. If your bike has any external oil lines, that is where your tap into the oiling system. Couple the oil cooler with one or two small fans on it and you'd have a relatively protected machine. But (there is always one, isn't there?) key areas like the center of the head, the exhaust valves are still going to run too hot and there is not much you can do about it on an air cooled bike. You sort of have the old "Rock and a Hard Place' dilemma.

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Your worring about nothing.......

as long as the fins are clear (not covered in mud) your fine.

Its not like your running a 12:1 compression.

If you really feel the bike is over heating and about to seize up, start reving it up and hit the kill button real quick so it starts to stall but will start back up... hold the throttle open while your doing this and the unburnt fuel will cool the cyclinder,

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All trials bikes have fans that run off a thermostat. If you can rig that up somehow, then just pick up 2 of those and put one on each side of the cylinder.

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Okay guys...I've searched for something similar, but nothing. If I accidentally duplicate it...tough. I understand that air cooled bikes need a constant stream of air to work at the correct operating temp, but what if you ride tight, technical trails with a big thumper, and its 100+ degrees outside? After the little scare I had concerning my oil temp (actually fried an egg on my crankcase...lol), I was wondering about this...what if you could wire up a 12V fan to the side of your cylinder that kicks in when your oil temp rises above a certain temperature? Or for simplicity's sake, even a handlebar mounted switch that you could turn on when you feel it's getting too hot down there? My bike doesn't have a oil cooler, and I'm feeling quite sorry for it on those hot days. Any advice/guidelines/cussing would be appreciated.👍

Air cooled doesnt need air flow. The fins are not to guide air around the head, but to increase surface area for dissipation. The more surface area there is, the better cooling or its ability to "get rid of heat". Its designed to keep cool, even under the most extreme conditions.

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True, but a little extra airflow wouldn't hurt things would it?

(That said, if the bike is overheating then you need to get to the root cause of this before you do damage. Maybe overadvanced ignition/weak mixture/low oil pressure etc?)

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airflow is needed to reduce head temps. it would be like letting your water cooled bike idle for 30 minutes without any cooling fans. its going to overheat

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Thanks for all the replies guys. I don't know what I'm gonna do about the oil cooler, since it's a dry sump engine and its oil tank sits in the frame. There aren't any loose oil lines that I can think of, but I'll know for sure by the weekend. I wouldn't know if it's running lean as I'm still waiting for my spark plug spanner to arrive (it's been 3 months now), but when I do I'll pull the plug and let you all know.

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a air cooled bike does not need a fan even if just sitting it should run forever, toyotatech is correct on every point 👍

you might get 10 deg head temp diff. with a fan maybe and thats if its always at idle or going 5mph going any faster a fan wont do anything at all. unless you add a oil cooler to the bike and put the fan on that that will cool the bike down.

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a air cooled bike does not need a fan even if just sitting it should run forever, toyotatech is correct on every point 👍

you might get 10 deg head temp diff. with a fan maybe and thats if its always at idle or going 5mph going any faster a fan wont do anything at all. unless you add a oil cooler to the bike and put the fan on that that will cool the bike down.

true. ive got a xr400 i can start that thing up and let it idle for a hour and the oil temp does not go over 175. i call it the generator :worthy:

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