New Member with Question about Yanmar Diesel

[never monday]

Originally Posted by calphi27

What is the fuel rack, Alan mentioned? Could that be it? Thanks again!!

The fuel rack is part of the IP. It controls the dose of fuel injected. I've temporarily ruled it out form your cut of cable comment.
If you want to verify it with a minor invasive technique. You can remove the throttle arm, 12 or 13 MM nut, then the 2 bolts holding on the throttle stop 10mm. This will allow the missing inspection cover to come to light. Slide the cover forward (it's notched under the throttle arm) and reach in with RUBBER GLOVED finger. there will be a bar running vertically see if if wiggles fore/aft easily with extra light pressure. If so, the rack is good.

[Alan Wheeler]

I second the comment Pat made about the Pump airlocking. Even just one bubble will stop the thing firing.
I wouldn't go delving into the inards of the thing yet. The rack having an internal issue would be rare. If everything is working on the external, then I imgaine internaly the rack is being moved along. Go with Pat and rule that out before going into the internals of the thing.

[calphi27]

Hey, Yanmar guys,
Your suggestions last nite reminded of an issue I completely forgot. Last season, after an oil change, my son & I tried to restart the engine. After some difficulty she cranked up and then "ran away". In spite of pulling the cut off cable, we could not stop the engine. After 2- 3 min off high rpms, she died. Does this suggest the problem my be in the cutoff cable, as you considered? You have convinced me to leave the IP alone. When I re-install the IP, the water pump,etc; do I need to use new gaskets? I really did not see any as I removed things? What seals it? I assume it's not like a gasoline engine I'm used to. Thanks for your help and ideas. I plan to be at the boat this wkend and try all of these great suggestions. james

[GordMay]

A note about the Yanmar Engine stop cable:
Yanmar’s oem engine stop cable is not made from Stainless Steel, and can rust ferociously, especially in salt environment.
To control the rust, disconnect the cable at the engine side, straighten out any kinks from the setting screw and pull out the cable in the cockpit as far as you can see rust development.
Remove rust with emery cloth and rust remover, and then generously coat with water-resistant grease.
Reinstall the cable, making certain that the engine stop lever is in the full “run” position, when the stop cable is pushed in all the way.

[Alan Wheeler]

OK this is seriouse. To runaway like that, does lead to the notion of a Fuel rack problem. The rack is stuck open for some reason. Start with the obviouse and easiest as in cables. Ensure all are operating all connections and levers on the outside of the pump correctly. Although a fule rack issue is not impossible, it is also very unusual. It is a robust piece of assembly inside. Now I am saying this with no actual experiance inside THIS particular pump. So I stand to be corrected. But the rack is a series of moving parts that one part could be either broken or jamming, stopping the release of the rack, which allowed the Runaway. It could also now be the issue of not opening. You may need to get the inspection cover opened and look at the rack.

[billangiep]

Just a side note to all the great advise above. If your turning over the engine more than a bit you may want to close the sea cock to keep the raw water from being pumped in your engine?
Bill,

[Badsanta]

Well, did you fix it???? inquiring minds want to know!!!

[Chief Engineer]

They are shims. Also when you install the pump you have to make sure that the small bar on the rack engages the fork. If not, you will have no throttle control and the engine may "take-off".

Originally Posted by calphi27

Hey, Yanmar guys,
Your suggestions last nite reminded of an issue I completely forgot. Last season, after an oil change, my son & I tried to restart the engine. After some difficulty she cranked up and then "ran away". In spite of pulling the cut off cable, we could not stop the engine. After 2- 3 min off high rpms, she died. Does this suggest the problem my be in the cutoff cable, as you considered? You have convinced me to leave the IP alone. When I re-install the IP, the water pump,etc; do I need to use new gaskets? I really did not see any as I removed things? What seals it? I assume it's not like a gasoline engine I'm used to. Thanks for your help and ideas. I plan to be at the boat this wkend and try all of these great suggestions. james

[calphi27]

I just have a few minutes for a little update. I worked on it last friday and winterized it. I noticed that the cutoff cable does not have the range that it used to. I think something is broken internally and maybe that is the problem. I can only move the arm, where the cutoff cable attaches, less than an inch. Would I have to remove the IP to work on this piece and troubleshoot it? The small hole near the arm seems too small an opening to properly work on it. Thanks again guys, you have been great!

[never monday]

Originally Posted by calphi27

I just have a few minutes for a little update. I worked on it last friday and winterized it. I noticed that the cutoff cable does not have the range that it used to. I think something is broken internally and maybe that is the problem. I can only move the arm, where the cutoff cable attaches, less than an inch. Would I have to remove the IP to work on this piece and troubleshoot it? The small hole near the arm seems too small an opening to properly work on it. Thanks again guys, you have been great!

The area you are dealing with is the governor system. It will require removal of the front cover of the engine to effect any repairs to it.

I still maintain this problem is simpler than we've been discussing.

Disconnect the cut-off cable from the engine. Does the arm still have full travel? as you push it toward the flywheel it will change resistance for the last 3/16 - 1/4 inch. Does this happen?
How much travel is there to the cut off arm from the full flywheel position forward?
Where is this boat?

I'm sure more would come to me in a conversation with you.

[calphi27]

I did disconnect the cut off cable and the arm has limited travel, about 50% less than it used to. When I looked inside the inspection port, the rod on the control rack was not engaging the fork (governor lever)! As I moved the arm it was hitting the rod on one side, which limited the travel. But the arm resistance does change the last 1/4 inch. So the problem is in the fuel rack? I can't see how one could repair it thru the very small inspection port? How difficult is it to remove the "front cover" and fix? If i get the rod back within the fork does that correct my problem? thanks!!! (we're in Oklahoma at Grand Lake with NO diesel mechanics!!)

[never monday]

Originally Posted by calphi27

I If i get the rod back within the fork does that correct my problem? thanks!!! (we're in Oklahoma at Grand Lake with NO diesel mechanics!!)

Yes, call me tomorrow during the day the number is on my web site. I'll talk you thru it. It's not as difficult as your imagination wants you to believe.

[calphi27]

Thanks Pat, will do tomorrow. james

[Chief Engineer]

That pin has to be inside the fork.....It is not difficult to do....If Pat says he can talk you thru it, terrific. I am just thinking how I would convey the messgae myself.

Let us know how you make out.

btw the shims go on one way....don't forget them.

[lateral]

I see this thread is somewhat old but quite relevant to my situation.
Perhaps someone who has "been there" can help with my problem.

My boat was pulled some seven yrs ago to fix a problem with mast compression on the step/hull. We ended up completely rebuilding the boat.(Ourselves, in spare- time from keelson up.)

It has been a extremely long & expensive road ,which even we, who don't balk easily at challenges, would never do again- for a variety of reasons. Life is too short. We are nearly at the summit of our "Everest".

-3GM30 500hrs -sitting for 7 yrs unused.
Refurbished-heat exchanger, fuel pump (new), mixing elbow(new),
mounts (new). Blasted & painted.
Today I set up for a w/shop floor start up, to make sure everthing was ok.
Bled fuel to IP & then cracked all three delivery pipes to injectors.
Ran starter mtr (decompressed) to chk for fuel. -Only fuel at number 1.
I have rebled & repeated but no sign of fuel at 2&3??
Could the plungers in 2&3 be stuck in the "up" position?

This thread has been quite informative so I am going to chk a few thing mentioned here.
For instance, the engine cutoff lever has only 15mm (< 5/8") travel & doesn't have a "firm bit" at the end of its travel. I have no idea what travel it used to have.

I am posting this with the hope of suggestions whilst I follow up on some points previously mentioned.
Cheers for the info