Trying to help a friend get dump truck running. I am a mechanic on medium speed diesels, but have never worked on a MACK... Engine was changed at some point. Info on valve cover says EM7-300, Serial 5R1096 can this be relied on 100%? The pad on block by air compressor has the following, 3U1539,, 2115M-326612.. Is this a EM7-300? Engine is not electronic, it is 4V head. Tried to adjust valves from #1 TC mark on flywheel comp stroke then followed firing order on block by bring up next cyl on compression stroke. Would not crank and could hear compression out exhaust. Backed off all Ex valves 1 turn and engine cranked.. Looked at flywheel for marking for valve adjustment, did not see any, do I need a better set of eyes. Is flywheel sometimes or always marked for valve adj. Thanks
