Yanmar SB8 injection regulator

[copaco]

I have found Adjustment of fuel-injection regulator on the web at WWW sailingthanksdad.com p.26
What is parallel to pump ajusting lever(c’ant be the punch mark).
In 4. They say tighten lightly the spindle.It is very hard to turn.I figured I would turn back ccw and then screw lightly.What can I do.Srew in and back of a1/4 turn.
I have turned back the connecting screw 3 to punch mark facing me but engine won’t start as before.

[Wotname]

Originally Posted by copaco

I have found Adjustment of fuel-injection regulator on the web at WWW sailingthanksdad.com p.26
What is parallel to pump ajusting lever(c’ant be the punch mark).

The screw slot on #3.

The first step is to carry out the adjustments numbered 1,2 and 3. This leaves the screw slot of #3 at 90 degrees to the pump adjusting lever (#1)

If further adjustment is required, you proceed with the second part numbered 1 to 6. In this instance, the screw slot of #3 ends up parallel to pump adjusting lever (#1) at step 3. Then at step 6 it is returned to be 90 degrees to pump adjusting lever (1).

In 4. They say tighten lightly the spindle.It is very hard to turn.I figured I would turn back ccw and then screw lightly.What can I do.Srew in and back of a1/4 turn.
I have turned back the connecting screw 3 to punch mark facing me but engine won’t start as before.

When the clamp (#2 & #8) is loose, the spindle #7 should turn fairly easily although there is a o ring inside that provides some resistance to turning it. The idea is that when it is turned CW to tighten it, you MUST NOT tighten it down hard. The other end of the spindle is a needle type valve and can be damaged by turning it too far. You tighten it until you just feel it stop and hold it by hand while the clamp is secured.

If you get it right, the arm (#1) is holding the spindle (#7) fully closed when the speed control is set to full power. If it isn't, then you haven't adjusted it correctly.

Note, there is only a few degrees of rotation of the spindle (#7) between stop and full power so it is easy to get it wrong the first time.

[copaco]

Greatly appreciated explanation.

[Wotname]

Also remember that you might have to bleed the injector pump after adjustment.

You can tell when everything is correct by listening for the injector "squeak". Set full power on the throttle, decompress the cylinder and crank the engine a couple of times - you should hear a squeak as the injector operates. If not, then there is either air in the system or the regulator arm/spindle is not adjusted correctly.

Please let us know how it works out.

[copaco]

Nice.I have the parts catalogue and I have noted the code numbers.I think new o-rings etc will help.Thanks again!

[Wotname]

Originally Posted by copaco

Nice.I have the parts catalogue and I have noted the code numbers.I think new o-rings etc will help.Thanks again!

If you pull the regulator valve out (and you will have to replace the o ring), look at the needle end very carefully, if you see any damage or wear, replace it - they are not expensive IIRC. This little easily damaged valve controls the amount of fuel delivered to the engine and any damage/wear is not good!

[copaco]

Works like a charm!Unbelievable ,nothing wrong with the engine,but you must really know what to do.
I hear like a click in the injector.
I’ved lowered the rpm quite a bit and no more hunting.
I guess I should not compress the compression spring to soon?
Should it idle with the cockpit lever in middle position notch?
Thanks a million.Been working on this since last summer.Paid 3 mechanics.They start the engine but that’s it (engine to old they claim).
There maybe a bad side to Facebook and all these technologies but there is a positif side also.If you were closer I would offer you a bottle of something.

[Wotname]

Congratulations and well done - you will be the local Yanmar SB8/SB12 guru before much longer. FWIW, the YSE / YSB 8/12 have the same setup.

While they are simple and bullet proof engines, they do require proper and careful adjustment but as you have found out, it can be learned! I had never seen one until two years ago when I completely rebuilt a YSE, including the injector pump.

I can't help with the cockpit lever position as I don't have one of that type but I suspect there is some adjustment with the inner and outer cables and maybe lever lengths. Make a note (or photos) of where everything is right now and then experiment - you can always put it back.

I having a virtual rum right now so

[copaco]

Just for curiosity sake.Would the two different procedures be for different engines or maybe the needle has two holes,one on each side?
.

[Wotname]

Originally Posted by copaco

Just for curiosity sake.Would the two different procedures be for different engines or maybe the needle has two holes,one on each side?
.

Curiosity killed the cat

The two adjustment procedures do slightly different things.

Consider the second procedure consisting of six steps as a full and proper adjustment and note that it leaves the punch mark at the 9 o'clock (if cylinder side is 12 o'clock and you are 6 o'clock).

After many hours of operation, some wear will occur on the regulator valve and when the sound of injection becomes indistinct, you carry out the first adjustment (3 steps) which leaves the punch mark facing you (i.e. 6 o'clock).

Note the difference in the punch mark positions at the completion of each adjustment.

In essence, you have tightened the regulator valve ever so slightly when doing the first adjustment.

Later, if more adjustment is required, you start agin with the six step procedure.

I have added some pictures of the regulator valve and arm etc which might help your understanding of what's inside. The O ring lives inside the brass / bronze body.

[Compass790]

I have to congratulate you Wotname on your success in coaching Copaco through a difficult problem that I know has defeated quite a few "professional" marine diesel mechanics locally.
Especially impressive given that I suspect English is not Copacos native tongue & he is a mechanical newbie.
He doesn't know how lucky he is to have a free "consultant" who can explain things in a clear & logical fashion & posts good pics
I to your writing skill & perserverance to achieve success
good onya mate

[Wotname]

Originally Posted by copaco

...........I think new o-rings etc will help.Thanks again!

Originally Posted by copaco

Works like a charm!Unbelievable ,nothing wrong with the engine,but you must really know what to do.
................

Copaco, I've been thinking about this again and I would caution about changing out the O ring unless there is fuel leaking out of the top of the regulator spindle /arm. If the engine is idling and powering up nicely, then I think it is better to "let sleeping dogs lie". I have found it difficult to refit the O ring but if it is leaking, then yes, give it a go - otherwise no.

Originally Posted by Compass790

I have to congratulate you Wotname on your success in coaching Copaco through a difficult problem that I know has defeated quite a few "professional" marine diesel mechanics locally.
Especially impressive given that I suspect English is not Copacos native tongue & he is a mechanical newbie.
He doesn't know how lucky he is to have a free "consultant" who can explain things in a clear & logical fashion & posts good pics
I to your writing skill & perserverance to achieve success
good onya mate

Thanks for your kind words cobber .

[copaco]

I second that.

[rockin411]

So glad I found this discussion. I have an SB12 and mistakenly took the fuel pump apart when I think all I needed to do was properly bleed the line - I missed the loosen the delivery valve step.

I'm a little confused how far to tighten the regulator spindle. There is a spring on the end that would push the needle closed so I wouldn't think you would tighten so far to compress the spring all the way? I'm a complete newbie to this diesel stuff but so far the SE12 service manual has been pretty good.

Also, when the needle is closed, is that full throttle or does that shut off the fuel supply?

Thanks

[Wotname]

Welcome to CF, rockin411, I'll get back to you later whenI have some more time re how much to tighten the regulator spindle but right now - only finger tight!

When the needle is closed, it is FULL throttle!

Again will explain more later