The Community Service was carried out in Beji Village, East Ungaran District, which consisted of 13 RW 51 densely populated RT. Most of participant work in the private and government sectors. Some of entrepreneurs are held fish farming which are managed by the community as an additional necessity for life. To sum up, the implementation of Community Service in Beji village, sub-district East Ungaran can be concluded as follows: Community service activities in Beji Village, East Ungaran District, Semarang Regency run well so that participants gained knowledge which can be implemented. Participants were given an explanation on how to make good Biofloc pond fish food and providing tarpaulins to partners as a form of concern for developing biofloc ponds.

The research method used was a qualitative experiment, starting with taking broken piston rings No. 2 and 3, cutting the piston rings and testing them with hardness tests and composition tests carried out at the Indonesian State Maritime Polytechnic and Undip Central Java Integrated Lab. From the results of this research, it can be concluded that the used broken ring number 3 has the highest hardness of 140.26 HB and the used ring number 2 is 131.50 HB, so it can be concluded that the piston ring that has been used and exposed to high heat causes an increase in hardness and causes it to break. The composition test results showed that the carbon content of the new ring no. 2 was the highest at 15.30% and that in the used ring no. 2 was 12.08% because the compression ring was in direct contact with the compression chamber or in contact with heat. For the used number 3 piston ring, the carbon content is 10.43 and the new one is 11.02 because it is positioned below the compression ring and is not in direct contact with heat. for the used ring no.2, the Silicon (Si) content is low, namely 2.15% compared to the new one, 2.75% because the nature of Silicium is that it is resistant to high temperatures and as a compression ring compared to ring no.3, fracture occurs because there are no Manganese or Phosphate elements. which is wear resistant, strong and elastic. The microstructure of piston ring No. 2 is broken and the new two piston rings are less dense and have rough gaps. The broken piston ring structure of No. 3 and the new one looks a bit gray and has high levels of graphite iron and carbon elements.

Community Service is an obligation for lecturers to carry out the Tridharma of Higher Education. The activity was carried out on June 18, 2022 in Jelamung RT 05 RW 02, Kemujan Karimujawa which was attended by 12 participants. The purpose of this service is to know how to maintain fishing boat outboard engines in general, which is used to change the engine oil, cleaning the air filter and fuel filter, testing the injectors and adjusting the valves, in addition it is to know the reason why the engine cannot start. Therefore, someone should check the fuel flow, opening the fuel filter and cleaning it. The implementation of this program is for fishermen’s beneficial, hance they can maintain and overcome engine damage for the sake of progress and increase the income.