very strange

[4speed]

I was doing some carb work on a friends bike 02 883 stock, got the bike running good so while at idle i pulled the oil plug and the bike almost died put it back ran fine,tried again almost died any clue on what this can be

[FLTRI]

Well, since it's not a state-of-the-art automobile with crankcase sensors to measure pressure/vacuum and will shut down the engine if the pressure reading is not right...this IS the strangest condition I've heard in a long time.

Did you notice if the plug wants to be pushed out or sucked in?
I honestly know of nothing that can cause this unless there are other signs the engine is not running properly...then some testing can be done to diagnose the running issue...which may alleviate the issue.

So, if the bike runs fine otherwise...doesn't use/blow oil...I'm not sure if what you experienced is critical.
There's got to be more to the story...like what was the last thing done to the bike or if there are any other issues...etc
Bob

[4speed]

the bike sat for a couple of years it all stock,it started rite up just ran bad so that is when i did the carb she runs real good thats all i no

[FLTRI]

Vacuum at filler?
Pushes oil out the filler?
Oil added before running the bike? Oil level proper now that it has been run?
Let us know,
Bob

[4speed]

it just went away after a long ride

[Lew]

WoW, if only I could get em to do that.