Will a record weight harm the motor in a direct drive turntable?

I have used record weights on both my VPI HW40 and Technics SL1200GAE without trouble.  However I have also found a KAB record clamp to work as well or better for a lot less money and frankly prefer it.  

I think it's one of the snake oils. I never found any benefit in clamps or weights. 

Well whether there is any benefit to weighting or clamping is definitely record dependent.  For perfectly flat records, I agree that there is little or no benefit and in fact a weight can actually dampen or choke the sound a bit.  A clamp has no deleterious affect on the sound that I have been able to detect, however.  On records that are not perfectly flat, a weight or a clamp helps to bring the record more firmly into contact with the platter and that does two things:  It makes it easier for the arm/cartridge to track the grooves, and it dampens resonances in the record itself.  So saying they are snake oil is over stating the case.

Search Amazon for "record weight"and pick one 8 ounces or less.

I was surprised to find so many listings and just purchased a 5.5 ounce unit for $10  as I've yet to go that low in weight.

If you observe a SQ improvement with a lighter weight then further experiment from there if you wish.

How many here have experimented with 8 ounce (or less) record weights?

DeKay

In general Making a motor work harder can only shorten its life. 

It’s never a positive thing in that regard for sure.  

Each case is unique. The benefits need to outweigh the disadvantages.  Unless a table is explicitly designed and guaranteed to handle a certain amount of increased load beyond normal I would always proceed with caution. 
 

On the positive side,  adding weight near the center spindle is less problematic than if added further from center.