Jake Paul is racing to his brother's defense yet again ... this time calling the latest controversy surrounding Logan Paul complete "bulls***."

El Gallo sat down with TMZ Sports on Friday just hours after internet trolls dug up a four-year-old video that they claimed showed Logan pushing his dog off a speeding boat for clout -- and the younger Paul bro told us it was all a bunch of crap.

Jake explained Logan "cleared the air" on the drama when it initially came out nearly half a decade ago -- and he was pissed his older brother had to revisit the allegations once again this week.

Jake told us it seems like this is happening to Logan almost weekly (Maverick has found himself in headlines quite often this year) ... and he's ready for it to stop.

"I don't know what it is or who these people are that are planning these attacks on him," he said, "but, you know, it's bulls***."

"People just need to worry about their own lives and move on," Jake added, "and stop trying to find some dumb, fake s*** that someone did."

Jake clearly believes Logan's a good dude -- and he tells us he's excited as hell to become an uncle when the WWE Superstar's fiancee, Nina Agdal, gives birth in a few weeks. In fact, Jake called the whole thing "insane!"