Crf250r engine rattles when accelerating

Clacking noise with the 1.0 EcoBoost

Hydraulic valve lifters are as far as I know

simple valves in which the valve clearance is hydraulically compensated.

Therefore, no valve clearance has to be set and possibly readjusted for them.

They are briefly loud at the beginning because they have a little play and become quiet very quickly as soon as the oil pressure drops

the oil has pressed into the gap (clearance).

Please correct me if this is wrong.

I don't know what hydraulic valve lifters in the vacuum pump have to do?

Is there such a thing in Tourneo and if so, why?

And I'm really not sure if we (diesel / gasoline) have hydraulic valve lifters.

Because it "rings" every now and then when you step on the gas, or don't you think so?

I mean something like that which older among us still as octane ringing

in relation to the ignition timing (x degrees before TDC, etc.).

Whereby the current gasoline engines rely on the injection electronics on something like that

should stop and with the diesels, there shouldn't be exactly that.

But I only mean the sound itself and not its origin.

I mean to hear the valves every now and then?

So whether the auto-ignition is not so optimally timed every now and then?

Perhaps an engine spec can shed light on that?