This 2005 Honda CB900F 919 exhaust hardware selection offers two quantities of the listed port gasket: one piece or ten pieces. Use the shared replacement references to identify the gasket, then compare the package size with the work you have planned.
Replace one exhaust port gasket on your CB650, CB400, CB450, or modern CB900F with this Exhaust Port Gasket, 1 piece, replacing OEM #18212-634-000 /...
Stock up on exhaust port gaskets for your CB650, CB400, CB450, or modern CB900F with this 10-pack, replacing OEM #18212-634-000 / #18291-236-000 / #18291-MN4-920.Key...
Honda lists four 18291-MN4-920 port gaskets on the original 2005 exhaust. Both offered products include that replacement reference, with either one or ten gaskets supplied; neither listing is a complete exhaust mounting kit.
One sold-each gasket supplies one cylinder-head port position. Four singles provide the original four-port set; a ten-pack supplies spares beyond one complete four-port job. The listed application is the same for both package sizes.
Match the seal to the actual connection
The original exhaust also has separately numbered muffler and rear pipe joint packings. Those are not included in either port-gasket listing. If a joint is damaged or an aftermarket system is fitted, check its parts requirements rather than assuming a new port gasket will solve the leak.
Practical questions
Is one ten-pack the normal gasket count for this motorcycle?
No. Ten is the package quantity. The original cylinder head has four exhaust-port gasket positions, so a complete four-port renewal uses four of these gaskets.
Can the individual gasket be used at a muffler connection?
Do not select it for that location merely because it is an exhaust gasket. It replaces the cylinder-head port seal; Honda's muffler and rear pipe connections have separate packing references.
Does the original four-port count prove these fit an aftermarket header?
No. Four describes the original headpipe-to-head seal positions, not every header's gasket design. Check the exhaust maker's sealing instructions and specified gasket reference before ordering; neither package size establishes compatibility.
Not sure which part you need?
Send your model and year, plus photos of your existing part and any changes to the original setup.