Case Screw/Bolt Replacements

Dezdan

Dezdan

Well-Known Member
Just curious, what are your thoughts on replacing worn case screw/bolts? I'm not a purest, nor will any of my near future builds be, but should I stick to OEM bolts, or go after some stainless allen/hex head/philips? Pros/Cons? I don't mind the JIS (assuming new OEM is still JIS?), just curious of everyone's thoughts.

Also, as far as OEM, I put this list together, does this look correct:

Right Crank Case Cover:
6 SCREW, PAN (6X40) 93500-06040-0A
2 SCREW, PAN (6X65) 93500-06065-0A

Left Crank Case Cover:
2 SCREW, OVAL (5X12) 93700-05012-0A
1 SCREW, PAN (6X20) 93500-06020-0A
1 SCREW, PAN (6X28) 93500-06028-0A
1 SCREW, PAN (6X35) 93500-06035-0A

Crank Case:
1 SCREW, PAN (6X50) 93500-06050-0A
3 SCREW, PAN (6X60) 93500-06060-0A
4 SCREW, PAN (6X65) 93500-06065-0A
 
Last edited:
6

69ST

Well-Known Member
It's not like any of them are hard to source...or expensive. You pays your money and takes your pick. For a purist restoration, nothing but JIS will do. FWIW, Honda changed-over to hex heads with the new-gen motors. Gotta be careful with those, very easy to over-tighten. JIS screws make it more difficult to strip case threads, an inexpensive means of protecting case threads from young, first-time, mechanics. The tradeoff is the p.i.t.a. removal process.

For a non-stock application, Allens are the best compromise...imho.
 
cjpayne

cjpayne

Well-Known Member
I usually end up replacing the clutch cover screws with OEM hexheads. That way I get the right lengths. If the flywheel cover doesn't have the points access cover, I put hexheads there too.
 
cjpayne

cjpayne

Well-Known Member
racerx said:
FWIW, Honda changed-over to hex heads with the new-gen motors. Gotta be careful with those, very easy to over-tighten.

For a non-stock application, Allens are the best compromise...imho.
Click to expand...

I use a T-handle with a socket. Gives a great feel and you can spin them when removing/installing. Time saver too.
 
6

69ST

Well-Known Member
I use T-handle drivers with most engine fasteners. However, with Allen head replacements, I use screwdriver-handle drivers. That makes gauging torque, by feel, dead-easy.
 
hornetgod

hornetgod

Well-Known Member
racerx said:
I use T-handle drivers with most engine fasteners. However, with Allen head replacements, I use screwdriver-handle drivers. That makes gauging torque, by feel, dead-easy.
Click to expand...

In Naval aviation maintenance, we call that a "calibrated hand"
 
kirrbby

kirrbby

Well-Known Member
I like the look of the stock screws so I tend to lean that way. Plus, they're stock. But racer mentioned before that using Allen head screws makes for a easy, tidy tool kit for under the seat. That to me is a good reason to switch, when correct doesn't matter. You can also get button head cap screws with Allen head (socket, I think) drive. Those would look better to me.
 
T

TBoltUSA

Vendor
Vendor
We just came out with a set of factory type Phillips case bolts
(We had Allens for quite some time)
honda50-70EngineCaseScrewsSetOEMstyleTBW0820.jpg
 
6

69ST

Well-Known Member
kirrbby said:
I like the look of the stock screws so I tend to lean that way. Plus, they're stock. But racer mentioned before that using Allen head screws makes for a easy, tidy tool kit for under the seat. That to me is a good reason to switch, when correct doesn't matter. You can also get button head cap screws with Allen head (socket, I think) drive. Those would look better to me.
Click to expand...

When you build a real road bike, having a viable toolkit matters and real estate is seriously limited. A set of Allen wrenches occupies less cubic real estate than the standard open-ends. When you start getting into odd-sized (relatively speaking) fasteners, with custom setups, an efficient tool kit that fits the stock carrier takes some planning. As for the aesthetic side, I agree. Button heads have a nicely finished appearance.
 
Top