Well, got back from town last week to find my generator had stopped!! Copious quantities of fuel oil running down from the cylinder head looking very much like the injector body may have cracked, it looked terminal. I have avoided messing with injectors too much, understanding them to be a bit of a "black art". But no, these things are actually very simple. Turns out the constant high pressure spurts and time had slowly and surely worn a groove between the nozzle and the main body. Only one thing to do was to carefully grind a few thou back to good metal and lap the two together. This creates another problem.... the pingle valve is now too long, and once the nozzle and body are retensioned, it cannot move!!! After a few frantic cups of coffee to settle the nerves, figured a spacer may just be the answer here. The pingle vqlve is a lot like a fuel float valve in a carburettor, in this case its heavily spring loaded, the fuel pressure at something like 16 Bar lifts it a few thou off its seat, this is what causes the "creak" when turning the engine. The reason being to allow the fuel to attain a goodly pressure before it does the squirting.
I cut a disk from .2mm aluminium, and drilled a 1/4" hole through the center to clear the pingle valve shaft. Another .5mm hole was drilled to allow the flow of fuel from the body to the nozzle, and another 1/16" hole to accommodate the locating pin. Once together, I temporarily mounted it onto the injector pipe, a small prayer to Mr R A Lister, and wound it over. SUCCESS!! It took a few tries to adjust the spray pattern and check for leaks, but once fitted, the old girl fired up and ran just as good as always. I had noticed the injector weeping a little lately, and chose to ignore it wishfully thinking it will go away. It didnt. Now it has.
So, anyone on a budget, or unable to find a replacement, take the bull by the horns and have a shot at fixing it yourself. They are dead easy to dismantle, and a few moments thought will discover how they work. Just keep everything SCRUPULOUSLY clean, the slightest bit of shit will jam it up entirely.... clearances are minute. The pingle valve MUST move freely. The final injector tweek is done with the engine hot under a constant load. Adjust slowly the pressure screw under the top injector cover while watching the fuel rack position for minimum. This will also coincide with the cleanest exhaust, but interestingly, as I found, not the best spray pattern. This can be explained I think by the injector working into a high compression pressure when operating that we cannot see, but it looks wrong when squirting at atmospheric. Anyhow, another successful repair that took a few hours, and saved a heap of time and money, that has to be good. Its done a few hundred hours since with no leaks or issues.... insert happy face here.