knocking

[vinnie9000]

I'm new to the site and need some advice. The bike is an 84 KZ700 with around 7k miles on it. I've done most of the basic maint. on the bike such as oil, brakes, cables, plugs. The compression sits right around 150 on all 4 cylinders. When I start it up cold, I get a heavy knocking noise YouTube - KZ700 running . It goes away after 10 min or so of riding, but I really do like this bike and want to make sure it's not anything serious. Any ideas on what might be the cause?

[steell]

I listened to the video and couldn't pick the knocking out of the rest of the noise.

Get a 3 foot section of garden hose, place one end against your ear and move the other end around the motor to locate the place where the noise is loudest. That will localize the noise and allow me to probably identify it.

[vinnie9000]

actually the rest of the noise was my issue. There aren't many older bikes like this around where I live and I'm not sure what noises are acceptable and which aren't. Does the bike sound ok?

[steell]

Most of the newer bikes are water cooled, and that makes them a lot quieter than the air cooled KZ fours.

I couldn't hear anything that would give me reason to be concerned, but things sound a lot different when they're right in front of me

[vinnie9000]

Thanks!!

[kawpaul]

I would do the hose check trick that steell mentioned and see if you can locate exactly where it is coming from. These bikes do have a bit of valve noise at idle which is perfectly normal. Also you may be getting a bit of primary chain noise. You really need to isolate where it is coming from. If it is coming from deep within the engine then that needs further investigating. If it is coming from the valve/head cover area it is probably the valves.
Also with the tank on it is hard to tell exactly where the noise originates from because the sound will bounce off the tank.