Tight 1st Operation Seam
1st Operation Seams - Cause & Remedy

If the 1st Operation Seams are too tight, the bottom of the seam will be slightly flat throughout its length as illustrated; or the cover hook will be turned back into the body hook.

Tight-1st-Operation-Seam
Probable Cause Suggested Remedy
1st Operation Seaming Roll too tight Loosten 1st Operation Seaming Roll. Refer to the Parts List and Instructions or Service Manual for a complete adjustment procedure.
1st Operation Seaming Roll groove profile too narrow Replace 1st Operation Seaming Roll with a 1st Operation Seaming Roll having a wider groove profile.