I had a 4-108 and for the most part they are bullet proof but a little air will play havoc. I would bet two dollars that it's an air bleed issue. It's been a while but I believe there is a air bleed nut on the top of the injector pump
. There might be a bubble there. My system had a gravity feed fuel system but I put an electric fuel pump
in the system because the hand bleed pump leaves a lot to be desired. I also found that slightly cracking one injector connection at a time while the motor
is running will let the air out.
I now have a Westerbeke
that is the basic 4-108 block marined by Westerbeke
. They have added a few goodies that helps the air issue. Treat that Perkins
right and it will run for ever. They are great motors, they are heavy but I firmly believe that is what you want in a diesel