Jet Table saw motor issue

[bob pfohler]

A friend has an older jet JWTS 10jf table saw. When it’s colder than 70 degrees the darn motor won’t turn.
If he uses a block of wood and turns the blade really fast it will start running but it has to run 10 minutes before he can put any type of load on the motor.
He had it tested at a motor shop and they said it’s fine. Obviously it’s not, any ideas?

[Chris Luke]

Motor might be fine; what about the rest of the system? Two simple tests since it seems he's happy to pull the motor off, or at least remove the belts: Are the arbor bearings running freely when no motor is on there? Does the motor happily start without the drive belts?

[Frank Pratt]

Given that it's a cold temperature issue would mean that it likely has to do with bearings that have old, thick, crusty lube that needs warming up. It probably tested fine at the motor shop because it's nice & warm in there. It could also be the arbor bearings and/or a really stiff belt.