Helping out a friend that screwed up!

[itspaidfor]

Ok I have a friend in Davenport,Ia that bought an old generator powered by an 8v71DD. It was not running right so he decided to run the rack. LOL! It did not run away just the RPM'S where real high when he started it after his "Tune up job". Now I asked him about everything he did and I think I figured it out. He said he did not back off the low idle screw before he adjusted the rack. He did not touch the buffer screw. Now the question is I am going over tomorrow to try to get him out of this mess,if I back off the idle screw and reset the rack should this take care of it? I told him I thought it would but wanted to ask you guys first. Thanks in advance.....Dan

[Utahclaimjumper]

 If you have never done it you should not until doing so in the presents of one who has.>>>Dan

[itspaidfor]

Thanks Utah! I agree. I kind of chewed his but all ready. All he had to do was ask so hope full we can get it figured out.

[bevans6]

in the absence of a manual, back the buffer screw right out, back the idle screw right out, back the high idle lock nut off so you can adjust that if you need to. Put some vice-grips on a tube and start it, making sure that the engine stop lever puts the injectors in no-fuel.  Control the speed with the vice-grips.   Adjust the idle in to get it to idle fairly low, around 500 rpm.  Do a high idle (no-load max governed speed) run and see where it governs out.  Set the high idle to 2300 rpm or so.  Set the idle speed about where you want it.  Only then bring the buffer screw in to raise the idle speed marginally and smooth out the idle.  If you have a jake brake buffer switch start to test the jake activation on no-load.  If you haven't done this before, thank your lucky stars you don't own it...  There is so much that can go wrong with setting up a detroit from scratch.

In short form, back the idle off, back the buffer screw right out (remove it completely for that matter), then start it.   This all presumes the rack has been run right, which can't be done with the idle screw not backed off as far as I can recall.  To check the rack, put it in full fuel on the governor (engine off) and see if the individual injector racks see to be at full fuel, yet not locked into place, still a little loose,  Best way I can describe it.  Have fun.  It resembles nothing so much as balancing the carbs on an 8 cylinder motorcycle.

Brian

[luvrbus]

It not a problem he just adjusted not under full load

[itspaidfor]

Thanks guys!I was glad to hear he had not messed with the buffer screw! No jakes its a generator. I told him don't touch it. I will go over tomorrow back everything off & start from scratch. Thanks again.....Dan

[bevans6]

My advice is how to get it to run again safely, it's not in any way how to get it to run at proper speed for a generator under load...  that I have no ideas about.

Brian

[luvrbus]

There is no need to back the idle screw out if he has the spring type fuel rods the old 2 screw rods you could bend control rods without backing the idle out if not careful

[itspaidfor]

I will let you guys know what I find! Thanks again

[itspaidfor]

Just wanted to say Thanks Again! I backed out idle screw & buffer screw reset the rack & it is running great!  .......Dan

[wg4t50]

Being a generator, the governor will not be the typical DDC type, most likely a Woodward hydraulic.  In the end, who knows what the situation is, more nice DDC engines get killed by good intentions.  A picture would be nice.
Good Luck
Dave M

[luvrbus]

Dave I wondered about that also I never saw the DW governor on generators either but I guess it could be the way people cobble these old engines up now a days

[itspaidfor]

Yep had the same old govenor I have on my bus. It will be interesting to see what happens as he has not hooked a load to it yet. I would not even fool with it to be honest its to big to noisy and not efficient for a back up toy. Sometimes cheap is not the best!