Unknown motor, specifications interpretation and use
Your motor is 750 Watt and can be wired to work on 220v and 380V.
 It is likely that the wiring diagram for the motor shown below is applicable to your motor. This is a lower rated wattage unit.

The gearbox output is 40.5 RPM - about 1.5 seconds per rev.

Torque reading appears to be 145 Nm = 145 Newton metre or about 14.5 kg.m

Sanity check: Watts = RPM x torque in kg.m.
 So torque in kg.m = Watts/RPM
 = 750/40.5 = 18.5 kg.m =~ 182 Nm = about right.

14.5 kg.m will exert a "force" of 14.5 kg at a radius of 1 metre or 29 kg at 500 mm radius. That is very very ample for rotating a balanced BBQ pig of any sensible size. 

It is not too strong per se but will tear your arm off if you insist if you allow it to exert force at small radius.
 Say 15 kg at 1 metre, 150 kg at 100 mm. 750 kg at 20mm radius.
Do not try and arm wrestle with it!!!



The material below found here appears to relate to a Koncar motor of about half the current rating.

Connection as shown is  for 220V (I think) with alternative for 380 V (2 phase I think) shown on the connection plate. Testing resistance between the two input leads when in each arrangement should give a guide as to which is which - or if you can read Yugoslav.




PODACI NATPISNE PLOČICE


Cilj vježbe:
    Identifikacija vrste stroja i njegovih nazivnih podataka

Zadatak vježbe:
 a) S natpisne pločice ispitivanog stroja očitati potrebne podatke stroja: Un, In, Pn, nn, fn, cos Phi_n,   proizvođač, tip, serijski broj stroja (ili inventarski broj).
 b) Odrediti vrstu stroja i vrstu namota stroja.



1.3. Pitanja za pripremu vježbe:
 Nužno je poznavanje osnovnih podataka natpisne pločice ispitivanog transformatora 

a)  Koje najvažnije fizikalne veličine treba sadržavati natpisna pločica transformatora ?
 b) Kada se mijenjaju podaci natpisne pločice i zašto?
 c) Koje namote može imati asinkroni motor, kakvi namoti mogu biti i koji su osnovni načini spajanja namota ?   

1.4. Literatura:
 a) predavanje
 b) Wolf R.: Ispitivanje električnih strojeva I; skripta
 c) Nürnberg W.: Ispitivanje električnih strojeva.
 d) Avčin, Jereb: Ispitivanje električnih strojeva   



Another refence document of probably some degree of  relevance
 Koncar 3 phase induction motors. Various versions of the %Az and 80B - none seem to exactly match yours at a glance but one may. Mainly rating information.