KnockingClacking Heard in Carbeurator Under Load

I have a knocking/clacking sou

I have a knocking/clacking sound heard under the flame arrestor / carb that happens around 2k RPM+ while under load (in gear). It barely happens in neutral from 1500-3200rpm. I changed all the plugs and still the same problem. Please help!

"Try this (and it takes tw

"Try this (and it takes two people): Manually add a bit of choke while at this speed to see if the sound goes away.

If the sound goes away your timing may be too advanced, or your carb isn't getting enough gas. (Both bad news that need immediate correction.)

If the sound does not change, you either have a bearing knock, a really bad trans coupler (that should be noisy at idle speed), or a blown head gasket. If it's the latter, do NOT run the motor or you'll fire-slot the block and ruin it. A compression test will tell you if a head gasket is shot.

Jeff"