Petcock Rebuild Kit (Original Keihin) | Honda CB350 / CB360 / CB450
Fuel leaking from your petcock, or not enough fuel getting to the carbs at full throttle? The O-rings and gaskets inside the original Keihin petcock dry out and crack over time. This kit has everything you need to rebuild it — no need to replace the whole unit if the body is still in good shape.
Why You Need This
The original Honda petcock is a well-built fuel valve, but its rubber seals don't last forever. The most common symptoms are fuel leaking from the lever or sediment bowl, and restricted flow at full throttle from a clogged or deteriorated internal filter screen. The proper fix isn't adding inline filters to the fuel lines — it's rebuilding the petcock itself. The internal filter screen is all that's necessary to keep your carbs clean.
This kit replaces the three seals that wear out: the lever gasket, the sediment bowl O-ring, and the petcock-to-tank gasket. Clean the petcock body and filter screen thoroughly during the rebuild and your original Keihin fuel valve will flow like new.
Specifications
| Spec | Detail |
|---|
| Replaces OEM Part Numbers | 16953-283-000, 16955-283-000, 16956-283-000 |
| Fits Models | CB350 K0–K5 (1968–1973), CL350 K0–K5 (1968–1973), SL350 K0–K2 (1969–1972), CB360G/T (1974–1976), CL360 K0–K1 (1974–1975), CB450 K0–K7 (1965–1974), CL450 K0–K6 (1967–1974) |
| Sold As | Complete rebuild kit (3 seals) |
Note: This kit only fits the original OEM Honda Keihin petcock. It will NOT work with the Common Motor Aftermarket Petcock or any other reproduction. If you have a CMC aftermarket petcock that needs rebuilding, use the Aftermarket Petcock Rebuild Kit instead.
Does NOT fit: Honda CB350F (four-cylinder — uses a different petcock), CB500T, CB500K, CB550, or CB750. Those models use different petcock designs with different seals.
What's in the Kit
- Lever gasket
- Sediment bowl O-ring
- Petcock-to-tank gasket
Installation
Difficulty: Beginner
- Drain the fuel tank — Turn the petcock to OFF, disconnect the fuel lines, and drain any remaining fuel from the tank.
- Remove the petcock — Hold the petcock body and unscrew the large mounting nut from underneath the tank.
- Disassemble — Remove the faceplate screws, faceplate, lever, wavy washer, and sediment bowl. Note the position of all parts.
- Clean everything — Clean the petcock body, filter screen, and all metal parts thoroughly. The small mesh filter on the reserve line is often missing on older petcocks — don't worry if yours is gone.
- Install new seals — Replace the lever gasket, sediment bowl O-ring, and petcock-to-tank gasket. Use a small dab of light grease on the lever gasket for smooth operation.
- Reassemble — When reinstalling the faceplate, make sure not to pinch the wavy washer between the petcock body and faceplate — this will cause a leak.
- Reinstall on tank — The large mounting nut goes back on smooth side up. Thread it counterclockwise onto the petcock about half a turn only. Then hold the petcock in place against the tank and turn just the nut — both sides thread into the nut equally, meeting in the middle and sealing on the O-ring. Snug only — do not over-tighten.
Brass nipple tip: If your brass fuel line nipples have gotten pulled out of the petcock body, a few light taps with a copper or plastic mallet will seat them back in.
Our "5 Small Maintenance Jobs" video covers petcock rebuild along with rear brake adjustment, gas cap seal replacement, handlebar dampers, and exhaust gaskets.
Frequently Asked Questions
Will this fit the Common Motor aftermarket petcock?
No. This kit is specifically for the original OEM Honda Keihin petcock. If you have the CMC aftermarket petcock, use the Aftermarket Petcock Rebuild Kit instead.
Do I need to add an inline fuel filter?
No. The internal filter screen inside the OEM petcock is all that's needed to keep fuel clean going to the carbs. Inline filters can actually restrict fuel flow at full throttle on these bikes.
My petcock still leaks after rebuilding — what's wrong?
Check that the wavy washer isn't pinched between the body and faceplate. Also make sure the large mounting nut is installed smooth side up and only threaded about half a turn counterclockwise before mounting to the tank. Over-tightening the mounting nut can distort the seal.
Does this fit a CB350F or CB550?
No. The CB350F (four-cylinder), CB500T, CB500K, CB550, and CB750 all use different petcock designs with different seals. This kit only fits the twin-cylinder CB350, CL350, SL350, CB360, CL360, CB450, and CL450.
The small mesh filter on my reserve line is missing — is that a problem?
That filter is commonly missing on older petcocks. The main internal filter screen does the heavy lifting — the reserve line mesh is secondary. Your petcock will function fine without it.
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Last updated: March 2026
