Last year I changed the machine engine (PfaFF 1222 E). I noticed immediately that the machine sewed too slow and I thought it was a problem of the kind of engine the repairer had put into the machine. But...
If the machine did sew fast the the replacement motor, then the problem might be that the machine is getting gummed up somewhere. Pull off the top cover, remove the 5 screws from the bottom of the base plate, (4 large screws, 1 small screw), remove the base plate remove the 1 screw from the bottom of the free arm cover. Now you can see most of the moving parts. Spray a little WD 40 on all the areas that you see metal to metal rubbing together, both on the bottom side of the machine and the top side. Don't flood the machine and stay away from the motor area. Plug the machine in, lay it on it's back and run it full speed, or at least till it runs full speed. After you free it up, blow out the machine with compressed air, and reoil with tri flow all the areas again. Run the machine again, and you've started your own tail gate repair shop.
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