Iron Sportster bill of material


Blog BOM Custom Design
Garage OSARM Repair Smörg

Screw or bolt

Early model steel primaries used a 10-24 screw right at the bottom. Apparently the engineers could not get a 1/4-20 bolt to fit. Later aluminum primaries also need a 10-24 screw. Later models just have an oddball bolt length, so I included those in this category, hence the name. Hip enthusiasts know a bolt is 1/4-20 and larger while a screw is #12 or smaller.

2669


 Sportster_Engine_Primary_Primary-cover_2669_screw_1958-1963 Sportster_Engine_Primary_Primary-cover_2669_screw_1958-1963 CAD
Blueprint
10-24 screw used on bottom of steel primary cover. Problems: Straight slots get torn up by screwdrivers. Image credit: Harleyhummer.com.

2669W


Maybe a different finish or head on the 2669?

2421W

 Sportster_Engine_Primary_Primary-cover_2421W_screw_1967-1970 Sportster_Engine_Primary_Primary-cover_2421W_screw_1967-1970
Screw, 10-24 x 1 3/4" countersunk head. Problems: Straight slots get torn up by screwdrivers. Image credit: Jan Willem Boon - parts for your Harley-Davidson - database.

2422W

 Sportster_Engine_Primary_Primary-cover_2422W_screw_1971-1976 Sportster_Engine_Primary_Primary-cover_2422W_screw_1971-1976
Screw, 10-24 x 1 7/8" pozidriv fillister head. Problems: Posidriv not exact for Phillips tools. Image credit: Jan Willem Boon - parts for your Harley-Davidson - database.

3478

 Sportster_Engine_Primary_Primary-cover_3478A_bolt_1981-1984.JPG Sportster_Engine_Primary_Primary-cover_3478A_bolt_1981-1984.JPG
Bolt, grade 8, 1/4"-20 x 2 1/2" knurled socket head. The -A is probably due to the lockpatch. Problems: Can never pick the right Allen wrench size. Image credit: Jan Willem Boon - parts for your Harley-Davidson - database.