Lower Allen Bolt Kit | Honda CB350 / CL350 / SL350K0
The factory Phillips head screws on the Honda 350 engine side covers strip out — it's practically inevitable. Every time you pull a cover for routine service, you risk rounding another head. This stainless steel Allen bolt kit replaces all the lower engine cover fasteners with socket head cap screws that won't strip and look clean doing it. Allen wrenches and a bolt-position diagram are included.
Why You Need This
Honda used Phillips head screws on all the 350-series engine covers. They corrode, they strip, and they make routine maintenance harder than it needs to be. Allen (socket head) bolts grip positively with an Allen wrench — no cam-out, no stripped heads, no frustration. Stainless steel resists corrosion and keeps your engine looking sharp.
This is the Lower kit — it covers the side covers (left and right), chain cover, oil pump cover, and electric starter. The optional Upper Allen Bolt Kit is available as a checkbox add-on and covers the cam end holders, intake manifolds, cam box to cylinder head, points cover, tach drive cover, and tach cable.
Specifications
| Spec | Detail |
|---|
| Replaces OEM Parts | 93500-06028-0A, 93500-06028, 93500-06035-0A, 93500-06036, 93700-05016-0B, 93500-06025-0A, 93500-06025, 93500-06032, 93500-06032-0A, 93500-06040-0A, 93500-06040, 93500-06055-0A, 93500-06056, 93700-06040-0A, 93700-06040 |
| Material | Stainless steel |
| Sold As | Complete lower kit with Allen wrenches and bolt-position diagram |
| Fits Models | CB350 K0–K5 (1968–1973), CL350 K0–K5 (1968–1973), SL350 K0 (1969–1970) |
SL350 Owners: This kit only fits the SL350 K0. If you have an SL350 K1 or K2, the side covers are cast differently (no electric start) and use different bolt lengths — use our Lower Allen Bolt Kit for SL350 K1/K2 instead.
What's in the Kit
- Side cover bolts — left & right
- Chain cover bolts
- Oil pump cover bolts
- Electric starter bolts
- Allen wrenches
- Bolt-position diagram (paper sheet showing where each bolt goes)
Optional Add-On (Upper Kit) Includes:
- Cam end holder bolts
- Intake manifold bolts
- Cam box to cylinder head bolts
- Points cover bolts
- Tach drive cover bolts
- Tach cable bolt
Installation
Difficulty: Beginner
- Remove the old Phillips screws with an impact driver — this prevents stripping the heads on removal.
- Clean the threaded holes in the engine cases.
- Apply anti-seize compound to the threads of the new Allen bolts.
- Thread the bolts in by hand first, then tighten with the included Allen wrench.
- Snug evenly and do not over-tighten — these thread into aluminum cases.
Tip: If you're pulling covers for service, grab a CB350 Service Gasket Kit so you have fresh gaskets ready to go.
Frequently Asked Questions
Does this fit the CB350F (the four-cylinder)?
No. The CB350F is a four-cylinder model with a completely different engine architecture. This kit is for the CB350 / CL350 / SL350K0 twins only. We don't currently offer an Allen bolt kit for the CB350F.
Does this fit my SL350 K1 or K2?
No. Starting with the K1, Honda recast the SL350 side covers to remove the electric start and changed bolt lengths. Use our Lower Allen Bolt Kit for SL350 K1/K2 instead.
Does this fit a CB200, CL200, XL350, or other Honda model?
No. This kit is sized specifically for the CB350 / CL350 / SL350K0 twins. We don't currently support the CB350F (four-cylinder) or the XL350 (single-cylinder), and we make separate kits for the CB175 / CL175, CB200 / CL200, CB360 family, and CB450 family.
Does this kit cover all the engine bolts on my CB350?
No — this is the Lower kit only. It covers the side covers, chain cover, oil pump cover, and electric starter. The Upper Allen Bolt Kit (available as a checkbox add-on) covers the cam end holders, intake manifolds, cam box to cylinder head, points cover, tach drive cover, and tach cable.
What torque should I use on these bolts?
Snug evenly and don't over-tighten. These thread into aluminum cases, so the goal is even sealing pressure on the gasket, not maximum torque. If you're rebuilding the engine and want a torque value, follow the factory spec for crankcase cover bolts on your bike. Apply anti-seize to the threads to keep the bolts from galling next time you pull a cover.
Can I reuse my old gaskets when swapping the bolts?
If the gaskets are in good shape and you're not pulling the cover all the way off, you can reuse them. If you're doing a full service or rebuild while the covers are off, replace the gaskets with a Service Gasket Kit or Overhaul Gasket Kit.
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Last updated: May 2026
