Oil is not getting to the chain and bar, may be clogged.

A BRAND and MODEL # would help..
 
There is a filter in the tank, that should be the first to check.
 
As for next checking/cleaning, we need to know what it is...
 
 
 
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widucl
Remington RM 1645 Electric.
 
Thanks, Duane
 Oh, how do I get to the filter mentioned in the oil reservoir?

Open the filler cap and peek inside.  Fish the filter out with a coat hanger.
Filters about 3/4 long, maybe .5" in diameter.  Remove it from the hose and use brake
cleaner to spray from the inside out.  
 
Now you can pull off the chain side cover.  You may see a thinnish black hose(not sure how it's routed).
You want  to make sure that's clear of crap, brake cleaner again..  
 
If still not happy, spray brake cleaner from/into the inside tank hose while activating (chain OFF)
the unit.  Brake cleaner and if you have compressed air is your friend.. 
 
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