Oil Change Gasket Kit | Honda CL450 / CB450 / CB500T
The CB450 family is Honda's DOHC parallel twin — same centrifugal oil filter architecture as its smaller cousins but a different engine altogether. The centrifugal filter rotor needs cleaning every other oil change, and that means a fresh batch of gaskets and O-rings each time the right side covers come off. This is exactly that — the six gasket types that get disturbed during a routine oil-and-filter service on a CB450, CL450, or CB500T.
Why You Need This
Honda paper gaskets and O-rings compress against the mating surface during the first install. Pulling them off and refitting them produces a poor seal even if they look intact. O-rings take a set and won't return to their original shape. Reinstalling old gaskets is what leads you back into the same job a month later chasing a slow leak.
The Oil Change Kit (#4019) covers what gets disturbed during the standard 1,500-mile service: the three stator rotor cover bolt O-rings (Letter A), the oil rotor O-rings (B and C), the oil filter cover O-ring (D), the right crankcase cover gasket (E), and the stator rotor cover gasket (F). If you are going deeper — carbs off for an intake reseal, valve cover off for valve adjustment, or a full top-end — step up to the Service Kit (#4064) or Overhaul Kit (#4035) instead. Our gaskets are custom-made in the U.S.A.
Specifications
| Spec | Detail |
|---|
| Replaces OEM Part | 91301-426-010, 91301-393-000, 91309-286-000, 91312-PC6-003, 91305-283-000, 91355-415-000, 91307-283-000, 91304-HB3-003, 91302-943-003, 91302-200-000, 11394-292-306, 11394-292-010, 11394-292-000, 11691-283-306, 11691-283-000 |
| Fits Models | CB450K0 (1965–1967), CB450K1 (1968), CB450K2 (1969), CB450K3 (1970), CB450K4 (1971), CB450K5 (1972), CB450K6 (1973), CB450K7 (1974), CB500T (1975–1976), CL450K0 (1967), CL450K1 (1968), CL450K2 (1969), CL450K3 (1970), CL450K4 (1971), CL450K5 (1972–1973), CL450K6 (1974) |
| Sold As | Sold Individually (6 gasket types, 8 pieces) |
Note — Oil Choice: Use SAE 10W-40 or 15W-40 100% mineral only. The CB450 family has a wet clutch that shares oil with the engine. Modern semi-synthetic and full-synthetic oils contain friction modifiers that cause clutch slip. As of late 2023, Shell Rotella T4, Chevron Delo 400, and Mobil Delvac 1300 reformulated to semi-synthetic and now cause clutch slippage in these engines. Add 2 oz of zinc (ZDDP) additive per US quart with every oil change.
Note — Centrifugal Filter, NOT a Paper Cartridge: The CB450 / CL450 / CB500T does not use a replaceable paper oil filter. The "filter" is a centrifugal rotor inside the right crankcase that throws particulates against its walls; you clean it by removing the oil filter cover on the right side. You do not need a separate filter element, only the gaskets and O-rings in this kit.
What's in the Kit
Six gasket types, 8 pieces total. Letters A–F cover the routine oil-and-filter service. Letters G–J are added in the Service Kit (#4064) and Letters K–V in the Overhaul Kit (#4035):
- A — Stator Rotor Cover Bolt O-Rings (qty 3)
- B — Oil Rotor O-Ring (qty 1)
- C — Oil Rotor Cover O-Ring Small (qty 1)
- D — Oil Filter Cover O-Ring (qty 1)
- E — Right Crankcase Cover Gasket (qty 1)
- F — Stator Rotor Cover Gasket (qty 1)
Full CL450 / CB450 / CB500T kit-comparison chart:
Honda CB450 / CL450 / CB500T Gasket Kits| Kit | Letter | Gasket | Qty |
|---|
#4019
Oil Change Gasket Kit
(Includes Gaskets A-F) | A | Stator Rotor Cover Bolt O-Rings | 3 |
|---|
| B | Oil Rotor O-Ring | 1 |
| C | Oil Rotor Cover O-Ring Small | 1 |
| D | Oil Filter Cover O-Ring | 1 |
| E | Right Crankcase Cover Gasket | 1 |
| F | Stator Rotor Cover Gasket | 1 |
#4064
Service Gasket Kit
(Includes Gaskets A-J) | G | Intake Manifolds Gaskets | 2 |
|---|
| H | Points Cover Gasket | 1 |
| I | Valve Cover Gasket | 4 |
| J | Left Crankcase Cover Gasket | 1 |
#4035
Overhaul Gasket Kit
(Includes Gaskets A-W) | K | Cylinder Base Gasket | 1 |
|---|
| L | Camshaft End Cover Gasket (Behind Points) | 1 |
| M | Camshaft End Cover Gasket | 3 |
| N | Cam Tensioner Gasket | 1 |
| O | Exhaust Gaskets | 2 |
| P | Head Gasket | 1 |
| Q | Top Cam Chain Roller Shaft Sealing O-Ring | 1 |
| R | Alignment Dowel Seals | 2 |
| S | Cylinder Base O-Rings | 2 |
| T | Valve Guide Base O-Rings | 4 |
| U | Rocker Shaft O-Rings | 4 |
| V | Dipstick O-Ring | 1 |
| W | Valve Stem Seals | 4 |
Installation
Difficulty: Intermediate — the oil drain itself is easy; the rotor clean requires removing the right side cover and pulling the filter rotor cap.
Service intervals (per CMC):
- Engine oil: every 1,500 miles / 2,400 km
- Centrifugal oil filter rotor: every other oil change (≈ 3,000 miles / 5,000 km)
Procedure:
- Drain the oil warm: Run the engine to operating temperature, kill it, place the drain pan under the engine. Pull the drain plug and let it drain fully. Inspect the drain plug for thread damage — replace if pinched (drain plug is sold separately).
- Remove the right crankcase cover (when cleaning the filter rotor): drain residual oil, pull the kick-start lever, remove the cover bolts. The Right Crankcase Cover Gasket (Letter E), the three Stator Rotor Cover Bolt O-Rings (Letter A), and the Stator Rotor Cover Gasket (Letter F) come off with the cover.
- Pry off the 45 mm snap ring and remove the oil filter cap. Wipe clean built-up sediment from the rotor cavity with a lint-free cloth. Inspect the oil pick-up screen and clean if needed.
- Replace gaskets and O-rings dry or with a thin film of light sealer like Gaskacinch. Do NOT use RTV silicone — excess silicone breaks loose and can block oil passages downstream.
- Reinstall the right crankcase cover with the new gasket (Letter E). Apply a light coat of white lithium grease on the gasket sealing surface so the cover releases cleanly on future service. Tighten the cover bolts in a cross pattern, snug but not crushed.
- Refill with 2.9 US qt / 2.8 L of SAE 10W-40 or 15W-40 100% mineral oil. Add 2 oz of zinc additive per US quart. Run the engine, let it settle, and recheck the dipstick (unscrew, wipe, set back — don't thread in — remove and read).
Installation Tip: Clean the gasket surfaces very well, removing all old material and silicone residue. A light coat of white lithium grease on the new side cover gaskets makes them release cleanly the next time you take the cover off.
Our CB450 / CL450 / CB500T oil change walkthrough covers drain plug, refill quantity, oil grade, and zinc additive dose. The deeper filter-clean procedure (the part that uses gaskets A, E, and F) is in our CB350/CB360/CB450 oil filter clean video.
Frequently Asked Questions
Do I need a paper oil filter for my CB450 or CB500T?
No. The CB450 / CL450 / CB500T uses a centrifugal oil filter rotor inside the right crankcase, not a paper-element cartridge. Cleaning the rotor every other oil change is the equivalent of swapping a filter on a modern bike. You only need new gaskets and O-rings — this kit covers them.
Will this kit fit my CB500T?
Yes. The CB500T (1975–1976) is the bored-out evolution of the CB450 DOHC engine and uses the same oil filter and side cover gaskets. The CB500T and CB450 share this kit, the Service Kit (#4064), and the Overhaul Kit (#4035).
Will this kit fit my CB500K, CB550K, or CB550F?
No. Those are four-cylinder bikes (different family entirely — SOHC inline-four), not the DOHC parallel twin CB500T. The CB500T name confuses a lot of customers — the "T" model is a twin and is the bike this kit fits. The CB500K / CB550K / CB550F four-cylinder bikes need a different gasket kit.
What's the difference between the Oil Change Kit (#4019), Service Kit (#4064), and Overhaul Kit (#4035)?
The Oil Change Kit (this one, Gaskets A–F) covers a routine oil-and-filter service: the right crankcase cover, the filter rotor, and the stator rotor cover. The Service Kit (#4064) adds Letters G–J — intake manifold gaskets, points cover, valve cover gaskets (4x), and the left crankcase cover gasket — for the standard mid-mileage service that includes valve adjustment and ignition timing. The Overhaul Kit (#4035) adds Letters K–V — head, cylinder base, exhaust, cam tensioner, rocker shaft O-rings, and the rest — for a full engine teardown.
I want to adjust my valves — is this the right kit?
No. Valve adjustment on the DOHC CB450 family requires removing the valve covers, and the four Valve Cover Gaskets are Letter I in the Service Kit (#4064). Order the Service Kit instead if you are doing a valves-and-cam-chain tune-up — you'll have everything in this kit plus the valve cover gaskets.
My CB450 starts hard-shifting after the engine warms up — is it my oil?
Likely yes. The CB450 has a wet clutch sharing the engine oil. Modern semi-synthetic and full-synthetic motor oils contain friction modifiers that cause the clutch plates to slip. Drain whatever is in there, refill with 100% mineral SAE 10W-40 (or 15W-40 diesel-truck mineral), add 2 oz of zinc additive per quart, and the shifting feel usually returns within a tank or two. As of late 2023, Shell Rotella T4, Chevron Delo 400, and Mobil Delvac 1300 reformulated to semi-synthetic and now cause this issue.
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Last updated: May 2026
