Some of the marlins can be a bit tricky if it has been pulled apart and not put back together properly i.e.the two screws that hold the trigger plate to the action, if they are over tightened the action will not cycle correctly. I inadvertantly did this with my marlin 7000 and cracked the plastic plate, after loosening the rear screw a quarter to half a turn the action would cycle properly but I ended up replacing the whole part and was just more careful when stripping down rifle for cleaning.

I would recommend not using engine oil for lubing your rifle buy some inox spray or proper gun oil and just google exploded view for your model of rifle and pull it down and give it a real good clean

Hope this helps

 

im not using motor oil or never will, im using some of the Deep Creep by Seafoam......cleans it pretty good, plus on the can it says it can be used for guns, the guy at the autopart store told me to use it, says it cleans them good and keeps them decently lubricated, i still have to bolt problem but its not at bad, it went away after i cleaned it really good (when you pull it too far back it will get stuck) but all in all it is a really good, accurate gun, i just need it to be sighted in correctly....but this week (hopefully) i am getting a Mosin Nagant

 

Looks like you got a good deal.
I have a 40 year old Marlin 22LR that I have run 1000's of rounds through.
The ammo you use will make a difference in reguards to jamming,
I stay away from really cheap ammo they have a waxy lube that gums up the chamber and barrel.
It really just depends on how many you shoot between cleanings .

 

i clean it about every time i shoot