Any way to check oil pump output? 250 es / sx

[tri again]

I don't see any way to check oil pressure but have heard some people pull off the
oil tube to the head and just spin the engine with the sparkplug out.

Guessing 1/2 cup of oil in 10 seconds?

Thanks

[atc007]

Crack the banjo bolt at the head w it running. Should be flowing nicely,,it won't squirt! Just a nice steady oil leak . My moneys on it being just fine : )

[tri again]

Thanks 007
I wonder why I get tunnel vision so bad when it's one of my machines.

Yeah, that intermittent chain, rocker noise is very discomforting.
Smoooooth as can be for a few minutes and then clackityclack for 20 seconds and then ok again.
I guess chain tensioner failure is very rare but the oil may have been factory from
25 + years ago although it was not disgusting or bad.
Thinking it may want an engine flush.

Guessing less than 10 hrs total from new on this one.

I just hate to ruin such a pristine engine for no good reason.