01-09-13, 10:42 PM
It is called an oil gallery plug and plugs the end of the main oil gallery which supplies oil under pressure to the crank bearings.There is also one on the other side directly oppisite. It can be used to check the oil pressure by removing the plug and attaching an oil pressure guage to it. When you replace the plug, replace the O ring also and tighten it to 8 Nm and do not overtighten it as it is easily broken.