Engine rebuild kit for the Honda CB/CL/SL350 twins. Time to rebuild? If you're diving in and doing the top end, honing the cylinders, replacing engine side cover gaskets and replacing some seals this is a great kit to have on hand! The piston rings are for the stock bore.

Gasket Set Includes

12391-286-306 - Gasket A - Cylinder Head Cover x1
12395-286-000 - Cylinder Head Cover C Gasket x1
12392-286-050 - Cylinder Head Side Cover Gasket x2
30372-286-320 - Point Cover Gasket x1
12261-286-030 - Cam case Gasket x1
12251-312-003 - Cylinder Head Gasket x1
14592-286-310 - Tensioner Holder Gasket x1
91302-001-020 - O-ring 30.8 Qty: 4
91304-287-000 - O-ring 69.8 x 2 Qty: 2
16229-286-000 - Carburetor Insulator Gasket x2
12191-312-000 - Cylinder Base Gasket x1
18291-286-030 - Exhaust Pipe Gasket x2
11394-286-000 - Dynamo Cover Gasket x1
11395-286-040 - Left Crankcase Cover Gasket x1
11394-286-040 - Right Crankcase Cover Gasket x1

Oil Seal Kit Includes:

Left Cylinder Head Cover Seal
Tachometer Seal
Right Crankcase Cover Seal
Countershaft Seal - goes behind front sprocket
Gear Shift Spindle Seal
Dust Seal - Fits over the clutch lifter under the left crankcase cover
Mainshaft Seal
Gearshift Drum Seal

Piston Ring Features:

Ductile Iron Casting (FCD) is superior to OEM rings which were sometimes made from steel.
Superior tensile strength, ductility and elongation compared to steel rings.
FCD is even stronger than regular cast iron.
FCD is used in many automotive parts, which require strength and durability.

Installation Tips:

Be very careful when installing the cylinder over new rings, it's helpful to have the proper tool to keep the rings compressed as you lower the cylinder over the pistons. Try to use only plastic tipped tools to prevent from scratching aluminum surfaces.
The Letter stamped on the top two rings should be facing up when installing them and stagger the ring gaps according to the manual.
Press your seals in straight with a seal driver or a socket with a slightly smaller OD than the seal. Both surfaces must be free of dirt to create an oil tight seal.
All sealing surfaces for gaskets must be clean and flat to make a proper seal, sometimes non-hardening sealant is necessary.

Piston Ring Order:

Top Compression Ring (silver outer rim)
Second Ring (black outer rim)
Bottom Rings (3 pieces - Spacer in the middle - 1 thin ring on either side)

Fits Honda:

CB350K Super Sport - 1970-1973
CB350G - 1973
CL350K Scrambler - 1970-1973
SL350K0 Motosport - 1969-1970 (Does not fit 1970 K1)

3 Reviews Hide Reviews Show Reviews

4
Good Kit, some issues

Posted by luke on 7th Dec 2021

Overall this is a great kit, it is missing the oil pump gasket. And most importantly the cylinder base O-rings are not correct, they are too large, this causes huge problems and requires a full top end rebuild to fix. source those elsewhere, i learned the hard way.
3
CB350 Gasket Set

Posted by Unknown on 20th Oct 2021

Good overall but missing two o-rings for the oil filter cover. These should be part of a complete overhaul kit, or it should at least be noted in the description that they need to be ordered separately.
5
A must for engine overhaul.

Posted by Kiz on 7th Jan 2019

If you are planing on refreshing your old cb350, do yourself a favor and get these. It comes with the oil seals and gaskets. I got them when I took the heads of a cb350 I recently purchased, and I needed gaskets. However, the oil seals are very necessary to replace while I was already there.