as you inject fuel sooner, the cylinders will see higher combustion pressures and its certainly possible the engine will run 'rougher'. Likely, it is the imperfections in fuel delivery, valves, and compression between cylinders that causes this.

make sure the linkage is not restricting the IP rack lever from coming to complete rest on the idle set pin. whenever you move the pump, you must readjust the linkage.


Running at advanced timing will not damage engine. (certainly, there is a limit) But it does increase the forces seen on the crank and bearings etc.


Best course of action is to have completed all maintenance items and ensure a healthy fuel supply and injection system before setting the injection timing. A smoother running engine will deal with advanced timing much better.

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