Originally Posted by keith.mcginnis
4 Bolts right?
How do I know if the crankcase seals are bad?
It might be nuts. It's been a while since I worked on one.
You need to test it. You'll need Stihl Test flange # 1118 850 4200, Sealing plate 0000 855 8105, Carburetor and crankcase tester
1106 850 2905 and Vacuum pump 0000 850 3500.
Or you could just take it to a dealer and let them do it.