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Fan blades turn slowly on Electric Window Fan-- how to fix?

The W B Marvin Mfg Company (of Urbana, Ohio) made wonderful window fans flanked by screens. The frame could expand sideways, so these fans fit into any window with a width of 22" or more (up to about 37"). Circulated the air, but kept the bugs outside!

I really like these fans, and I have several. One is not working well: the fan-blade assembly turns very slowly -- a single go-round takes about 3 seconds. I'm guessing that the motor needs to be oiled or to have some gunk cleaned out. Or maybe the problem is a bearing gone bad. Or...? Ideas? suggestions? instructions on how to fix this? I'm handy, but I've never done any repairs on small motors.

Too bad that Marvin Mfg went out of business.

Answered! View the answer I have this problem too

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Thanks for a different type of question.

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First, check to see that the fan blades turn freely by hand and coast after being spun. If rotation is in any way stiff, this is a sign of dirty, dry, or gummed bearings, which can slow the motor. Sometimes the bearings can become tight and binding which can also be an issue. You can possibly oil this.

Second, does the fan wobble at all? If for any reason the blade pitch is steeper on one or more blades than the motor is designed for, this will slow the motor. This can often be the cause of warping, or a blade being knocked off balance. This will also cause the fan to wobble or shake. You can bend the blades to a shallower pitch if they appear to be too steep, but be extremely careful as blade brackets can break easily.

Most fans made in recent years use permanent split capacitor motors, as they are efficient and reliable. However with age capacitors can drift in value. If the blades turn freely and are balanced, the cause of a fan running slowly is almost always a bad capacitor. The capacitor is a small black box or silver cannister with two or more wires attached, and is located inside the switch housing, motor housing, or inside a bell on top of the motor. It should be replaced with a capacitor of equal value, they are marked i.e. 6uf, 4uf, etc. Some fans have capacitors with two or more values, they should be replaced with the equivalent of those values by one or more capacitors

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good answer +

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Thanks! My quiet fan spins freely, no "gunk" or lube issues, but slow starting. After 5 minutes it runs whisper quiet and at proper speed all night. I'll check the capacitor and R&R same.

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Geez thank you..your a genius

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On target. Used a little WD40 to clean accumulated oil/dust from motor shaft/bearing and a little machine oil to lubricate and my old Air King window fan runs as smoothly as ever.

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The shaft needs some oil. its just dry. I came across this alot and oil it once a month and you can get 10 more yrs. out of it. do not put too much just enough to get it spinning again.

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Dwayne S, check the age of the question. Hopefully this got fixed over the last 31/2 years

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oldturkey03 no matter how old the question is, it is is still a problem for others (like me) and the answers are valuable information that can last for years.

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cd barber, absolutely. That is why the answer is still there.

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I have a small fan that run on small motor but the fan gives air backward

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Julistra will be eternally grateful.
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