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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: david32knyte on July 20, 2019, 05:43:36 AM

Title: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: david32knyte on July 20, 2019, 05:43:36 AM
Hi All
Just had brush melt down on '85 K100 - Fan was getting stiff and eventually burned out.

I have a spare one - Should I lubricate the shaft on the electric motor?
If so - What with? - 3in1, PTFE spray?

I know I should fit a SPALL but I'll do that when this one burns out.
(In due course oin other words)

Thanks

David
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: Laitch on July 20, 2019, 09:02:17 AM
Just to be clear: you know what you should do, but you aren't going to do it.

Are you intending to disassemble the motor? External application will likely wash off or attract dirt. .

A likely more effective way to keep the OEM fan from seizing is to install a switch into the system that allows operation of the fan at will without overriding its automatic function then turn on the fan for a few moments regularly.
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: david32knyte on July 20, 2019, 09:33:33 AM
Hi there

Yes it's true. I know what I should do.

But using the bike to get to work so just need the thing to keep running till I get more time to do it properly.

No not disassenbling the motor.
On my last one I dropped a few drop of 3 in 1 top and bottom of shaft and that free'd it up well. Then I realised my brushes had melted on closer inspection.

Do you or anyone know whether the shaft runs in a bush or mini bearing?

Thanks

David

Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: Laitch on July 20, 2019, 10:10:35 AM
But using the bike to get to work so just need the thing to keep running till I get more time to do it properly.

Do you or anyone know whether the shaft runs in a bush or mini bearing?
If you aren't disassembling the motor, what's it matter? Bearings. I'm more interested in understanding how you know the fan will keep working until you're ready to replace it.

Your OEM replacement is likely to operate ok if it isn't exposed to harsh conditions continually and is operated occasionally, until it doesn't. The Spal is recommended for its integrity and reliability, qualities I reckon a commuter would want sooner than later.
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: The Mighty Gryphon on July 20, 2019, 10:11:30 AM
Don't bother with lubing the shaft.  It will take longer to get the lube in there than the lube will last. 

While I can't say for sure, I'm pretty sure the shaft runs in an Oilite bronze bushing.  The application doesn't justify a ball bearing.

If you have a good used fan go ahead and use it.  The first one lasted nearly 30 years, the next one may still have a number of good years left in it as well.  I have an OEM fan in my RT that has 92,000 miles on it and it still works well.

The advice to install a manual fan switch is good.  Put one on your bike and use regularly.
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: david32knyte on July 20, 2019, 05:05:41 PM
Thanks for the tips.

Yes will run the old OEM fan till the next meltdown.

92,000 miles. That is good going!  I'd settle for 10K!


Best

David
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: johnny on July 20, 2019, 08:52:16 PM
greetings...

i spray down my bricks with pb blaster at least three times a year... i makes a point to getts that fan motor in there too...

will easily use a gallon of the liquid in a bug sprayer... once i used a bugg fogger in a coin car wash with the doors closed... im pretty sure that fogg soaked the fan motor...

i find this practice a vital componet of my maintenance regiment...

j o
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: Laitch on July 20, 2019, 11:08:35 PM
I spray down my bricks with pb blaster at least three times a year.
will easily use a gallon of the liquid in a bug sprayer... i find this practice a vital componet of my maintenance regiment...
It cures arthritis, too. :beer:
Title: Re: K100 '85 - Cooling fan - What's best way to lubricate electric motor shaft?
Post by: koapono on July 20, 2019, 11:25:52 PM
just a word of practical advice:
if you do install a remote/manual switch to operate cooling motor be sure and use it.
good practice to run the fan for 10 or 15 minutes every ride, that alone will prevent most failures attributed to shaft seizure.
simple but very effective.