Perkins Injector Repair Manual

[avazquez]

I would like to learn how to rebuild the injectors on my 4108. Is there a manual that explains the procedure?

[GordMay]

I wouldn’t think so, but you could see if these Perkins Shop Manuals tell you what you need to know:

Chapter “N”
http://www.fujiyachts.net/manuals/Pe...p%20Manual.pdf

Starting page 50
http://www.fujiyachts.net/manuals/Pe...20Handbook.pdf

[never monday]

This isn't a job I recommend for the average mechanically inclined individual. There are some sensitive parts inside, and require a clean room to build.

[avazquez]

I have worked extensively on the old 500 kva White Superior engines and their injectors. Of course every system has its tricks but I am sure anyone with common sense and a good set of appropriate tools and manuals can figure out how to repair a simple mechanical device. I try to learn how to repair most or all of the systems and components in my boat. It gives me a lot of security.

[Alan Wheeler]

Injectors are actually quite simple to fix. As long as you know what you are doing of course. But the "sticky" issue is that they require special test gear to set back up again. You will need a test pump. Can't remember the actual name sorry(oh my memory is bad) It is a hand operated pressure pump. The injector is fitted and you pull done the handle to build up pressure till the injector seat opens. Thee is a pressure gauge that tells you what the pressure is. Then you give the handle a thump to "crack" the "seat" open and watch the "cracking Point" pressure. While at the same time viewing the spray pattern. This pattern is also important and something you learn in your trade. Not something easily explained here.
An injector service person will have a range of spares. There are some internal parts that you will replace and some internal parts are simply adjusted. In the early life (still several thousands of hrs) of the injector, the repair maybe a simple clean and adjustment of the pressure spring. Oh and the fuel used to calibrate is a special grade fuel oil.
In my view, for the equipment one would need to do the job and the relatively cheap cost of having a pro do the job and the vast number of hrs between the job, it is simply not worth doing it yourself. It is also very very easy to damage the very small injector tip. You onley have to drop the thing and have it land butterside down, and you are up for a new tip. That is somewhat expensive.