Originally Posted by featherweightman

All machines are not the same.The black ones have gears inside.the white ones ..have a belt.The black ones have lube tubes on the motors.some of the white ones do not.the foot control on the black ones un pluges .some do some do not on the white.Let me try to make it simple.The motor on the white one is a more powerful motor..04 vs.0.58.The first fix i would try is simple.It s called motor burn out.Some of these machines have been setting for 30 to 40 years.Un hook belt from machine and run motor for 5 to 10 min.at high speed.IT may smell or it may get hot but after a while you will here the pitch change.When it does you will see a big difference in the speed.Ihave worked on a lot of featherweights and it works most of the time good luck ,let me know if it works.