I'm more comfortable with wood than metal, but enjoy doing stuff on my diesel IF it's routine stuff to keep it running well reliably. My Nissan diesel is a 60's design that was little changed over decades of manufacture. They may still be building them. One quirk is the injectors tips seat on a copper nozzle gasket at the base of the injector chamber. If you don't know this, you're apt to use the standard sealing washers that fit above the tip on the collar(in fact, that's what the injector rebuilder sent, they're standard Bosch injectors).

If you don't know these engines, parts can be hard to find. But I've learned that fork lift dealers still use these so they have any parts including these little copper gaskets.

But the trick is, they're not easy to remove as they fit snugly in the small recess the injector nozzle fits in which is above the swirl chamber over the piston. I spent a half an hour removing the first one. Then I ended up making a tiny pry bar by filing a pick to a chisel point which lifted the little rings on one try.

A diesel, especially the fuel system, is a plumbing intensive contraption if you ask me. I'm familiar with plumbing having done my own in houses for decades. With changing injectors, the high pressure lines and fittings are all removed. That includes a return line system, and then while I was at it, I changed the engine and primary filters. That's a lot of potential leaks, especially with old used fittings.

I've learned to treat each fitting in plumbing like the whole system depended on it, because, it does. So I tried to keep things extra clean as I worked with them. I also made sure I went step by step so you don't forget to remove or replace a gasket, tighten fittings evenly and in sequence.

It's always good to bleed the system, turn it over fuel off to get the engine lubricated, fire the glow plugs, and have the engine come to life. To see no black smoke off the stern was even better. It's amazing what boats have taught me.

Here are Nissan Gasket Nozzles, from a forklift dealer in Woburn, and my own custom made, magic pick, if you ever need them....