I have a PDF copy of a War Dept. JP3 generator engine manual. It's a 1.14MB file which I can email on request.
Salient points to Beeky's problem are: There is no need for periodic cleaning of the injectors, but inspection after 2000 hours is advisable. Instructions for dismantling and cleaning injectors are given, but it is stated that "cleaning should only be carried out under cover and under the direction of a mechanist or a fully qualified fitter-driver". Instructions are given for bleeding the injectors on refitting. A quick check on injector operation is that with the engine set for starting, with the crankshaft rotating you should be able to hear a creak from each injector as the nozzle works, and if you place your finger on the feeler pin on the top of the injector you should be able to feel the valve working. For starting, and running up to 1/3 load, the compression changeover valve handwheels should be screwed fully in (i.e. tight against valve seats) on all cylinders. For full load running, the valves should be screwed out to their fullest extent. If the engine subsequently runs on low load for more than 15 minutes the valves should be screwed back in again. Valves should never be left partially in/out, and all three valves should be in the same position. In a canal context, I guess this means you should normally run with the valves in, but if on a river, or towing etc, you should run with them out (except in locks). Black exhaust is stated to be usually a result of injector trouble or unsuitable fuel - I hope you are using the recommended War Dept fuel oil "Diesel" grade, purchased under the W.D. Running Contract for fuel oil and gas oil! Engine should be decarbonised every 1000 hours. Instructions are given for checking and adjusting valve clearances. David Mack
