Engine Clanking Noise, Just looking for thoughts Options

[Mblizzard]

In the process of installing my dual carbs I spent a lot of time listening to the engine. I notice what I would classify as an internal clanking sound on the number 3 cylinder. Which of course varied with engine speed but is present to some degree at idle. I recently reset the valves so I am fairly sure it is not that as it has none of the tapping sound I associate with valve clearance issues. It is much more of a clunk. Engine runs well and has good compression so I am thinking it is a problem that is much deeper.

This is a 1.8 with a big bore (96mm x 66mm) and a mild cam. I am thinking piston wrist pin? I will go back and check the valves before doing anything but I thought I would see if someone might have suggestions on other possibilities

Any thoughts on other sources?

[timothy_nd28]

Something changed. Engine was doing fine till he decided to install carbs a few weeks ago. Since then he had problems tuning the carbs, I'm sure the air cleaners were left off. It's very unlikely to have sudden bearing damage out of the blue, for just installing carburetors. However, the probability is much higher to have some FOD drop in thru the carbs. I've done it myself, dropping some silly engine tin screw in the intake.