*UPDATE 01/10/2025: Due to supply chain issues Honda Bond 4 may be automatically substituted for the equivalent gasket sealers (Three Bond Gasket Sealer or Permatex Motoseal Gasket Maker) based on what is available at this time. All of these products are the proper latex acetone-based sealer needed for the aluminum engine cases on your vintage Honda, not an off-the-shelf RTV silicone. If you have any questions about any of these gasket sealers, please reach out to us via our contact us page before making your order. Thanks - CMC Crew
Part: Honda-Bond 4 Gasket Sealer for Honda CT90, Trail 90 / CB100, CL100, SL100 / CB125, CL125, SL125 / CB175, CL175, SL175 / CB200, CL200 / CB350, CL350, SL350 / CB360, CL360, CJ360 / CB450, CL450, CB500T / CB500K, CB550K CB550F / CB750K, CB750F, CB750A motorcycles.
Why You Need This: This is Honda-Bond 4 semi-drying gasket sealer, often called Three Bond or Yama-Bond. This is one of the very few gasket sealers that you need to use on your vintage Honda Scrambler or CB. It is designed to be used in between aluminum parts that are face to face together. Parts such as crankcases (CB100, CB125, CB175, CB200, CB450, CB350, CB550, CB750) or valve covers (Late CB125SA, CB360) do not use a paper gasket, but rather a thin coat of Honda-Bond 4 on both sides of the mating aluminum surfaces.
This is not RTV silicone, which is the stuff that is sold at the auto parts store. We often see a repair that someone has used RTV silicone on, which is not the correct sealer to use on motorcycle engines. Sold as a 80ml tube, one tube will do many bikes. Use a little of this on the outer perimeter of any oil seals too to help avoid any leaks.
Installation Tip: Make sure your surfaces are clean and grease-free. Use some carb cleaner or acetone to remove any oil or grease from the sealing surface before applying the Honda-Bond 4. A very thin even coat is all that is needed on both sealing surfaces. We spread it out thin with our finger (in a glove). Do not squeeze on the sealer like toothpaste along the surface as it is easy to apply too much.
