TOPIC:

When I bought my '78 KZ1000, the stock airbox was there, but it was missing the silencer. I don't really know what that thing does beyond what its name implies, but I wanted to have a complete stock bike, so I picked one up on EBay.

There are two round holes on the top, and around the edge of each of the holes, there are 3 (I think) small holes--like screw holes, leading me to believe that there is supposed to be some kind of cover over these holes. Having not ever looked under the seat of a complete stock bike, I don't know what or if there is supposed. Are these holes supposed to be covered?

And what does the silencer do for me?

Here's what it shows in the parts diagram.

It doesn't show any discrete part that covers the holes, but I'm wondering what the screw holes around the big holes are for.



Post edited by: Skyman, at: 2007/05/03 13:36

Skyman wrote:

When I bought my '78 KZ1000, the stock airbox was there, but it was missing the silencer. I don't really know what that thing does beyond what its name implies, but I wanted to have a complete stock bike, so I picked one up on EBay.

There are two round holes on the top, and around the edge of each of the holes, there are 3 (I think) small holes--like screw holes, leading me to believe that there is supposed to be some kind of cover over these holes. Having not ever looked under the seat of a complete stock bike, I don't know what or if there is supposed. Are these holes supposed to be covered?

And what does the silencer do for me?

Short answers --
Are these holes supposed to be covered? NO.
And what does the silencer do for me? Reduces air intake noise.

Long answers --

Per FSM photo and cutaway drawing, there is no cover on top of the air cleaner silencer box. Just the two round unobstructed intake holes (no screen or mesh or wire guard or anything over the intake holes). The holes are the top ends of two cylinders (or tubes) going down into and almost to bottom of the silencer box. Air from the top goes into and down through and out the bottom of both tubes, and back up to where it passes through the single large tube into the air cleaner housing, through the air filter element, and then exits the air cleaner housing through the mesh screen just before entering the carb intake boots.

There appear to be "flanges" at the top of the tubes securing them to the silencer box, each flange having three round attachment spots where they connect to top of the silencer box. Could be brads, small grommets, or some other style semi-permanent fasteners. Shows nothing but the flanges on the top ends holding the tubes in place onto the silencer box.

There is a removable cap on the air box to allow removal and replacement of the air cleaner element.

Tough new laws regarding allowable emissions and sound levels began in 1976. This brought redesigned mufflers and air intake silencers. In later years, thicker "padded" case covers were also used (and probably some other features). All to reduce the overall sound levels involved.

The slightly louder air intake noise without the air silencer is hardly noticed while riding, but the difference actually can be heard when the bike is stationary and revved a little. The air silencer on my '76LTD goes unused to allow more underseat storage. Bet you'll miss the storage space.


Post edited by: Patton, at: 2007/05/05 04:09

Post edited by: Patton, at: 2007/05/05 04:13

delete dbl post

Post edited by: Patton, at: 2007/05/05 04:06

Thanks, Patton.

I think my silencer is missing the two tubes that extend down from the holes. All I see is two holes that open up to the "box" of the silencer. No tubes.