8v71 govenor

[Dietrichfarms]

I'm looking for someone who can check/reset the governor on my 1978 MCI 8v71. It has never worked since I bought the bus. Never a big deal as long as I was driving now with son inlaws I worry! I'm in central Texas by Brownwood, but can travel within reason. If I can get governor and bus ac recharged id be a happy bus nut!

[Zephod]

Which governor? The one on the air tank or the one on the engine?


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[B_K]

I'm looking for someone who can check/reset the governor on my 1978 MCI 8v71. It has never worked since I bought the bus. Never a big deal as long as I was driving now with son inlaws I worry! I'm in central Texas by Brownwood, but can travel within reason. If I can get governor and bus ac recharged id be a happy bus nut!

Which governor? The one on the air tank or the one on the engine?

Pretty sure he means the one on the engine!
Governors on the AIR system are not usually a problem.
  BK 

[Zephod]

Pretty sure he means the one on the engine!
Governors on the AIR system are not usually a problem.
  BK 

I'm puzzled because a governor on an engine does little more than limit maximum road speed. My bus has the governor set at 56 on the flat. I'm ok with that so I don't see any point in changing it. It makes me slower uphill but that's the only issue and it just plain doesn't bother me.

The governor on the air tank limits pressure to 125psi on most busses with the emergency relief valve releasing at 150psi. Now I'm pretty sure I'd want THAT governor working.


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[B_K]

Zephod
"I'm puzzled because a governor on an engine does little more than limit maximum road speed."

Is where your wrong!
See these old Detroit 2 strokes in these OVER THE ROAD COACHES truly are different animals than what you are used to in your skoolies!
I ain't try'n to put your skoolies or the knowledge of them you have down, just pointing out there is a LOT you don't understand about the BEAST of the over the road coach that most of us on this board own, know and work on.

The governor on a two stroke does two things it controls wide open throttle RPMs both under a load and w/o out a load! (it does NOT control road speed, it controls ENGINE speed)

And it is a very tricky piece to properly adjust and if one gets it wrong BOOM there goes a expensive lesson to the owner of said engine!

Yes Skoolies have governors that actually get signals from the speedo and limit the road speed but these big DD's are a totally different animal than what you'll find in ALMOST any skoolie.
  BK   

[Zephod]

I erred... the governor on my dt466 governs rpm. The governor on the Thomas I drive for work has a speed governor.


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[B_K]

I erred... the governor on my dt466 governs rpm. The governor on the Thomas I drive for work has a speed governor.

Exactly! But even that DT466 is a different animal than a real Detroit 2 stroke!
   BK 

[Utahclaimjumper]

  Also if not set up correctly a two stroke will not start reliably, the fuel will not meter properly and so forth,,many control items on a 2 stroke depend on a correctly set governor.>>>Dan

[baker4106]

Have you checked da book for 8v71.   I replaced my engine with one that the governor was disabled and it worried me.   I read the book and tried resetting the governor but didn't work right.   I reread dabook and followed it carefully and the second time I got it set at 2150 rpm.   I then increased the speed to 2350 to help when I shift.   One thing they don't say is when you remove the governor cover and then check the gap at 1000 rpm it will throw oil all over.   I have a 4106 with a stick shift and live in Michigan.

[Geoff]

Have you checked da book for 8v71.   I replaced my engine with one that the governor was disabled and it worried me.   I read the book and tried resetting the governor but didn't work right.   I reread dabook and followed it carefully and the second time I got it set at 2150 rpm.   I then increased the speed to 2350 to help when I shift.   One thing they don't say is when you remove the governor cover and then check the gap at 1000 rpm it will throw oil all over.   I have a 4106 with a stick shift and live in Michigan.

The DD 2-stoke uses a somewhat complicated governor system.  The governor gap has to be right before you can proceed with the injector rack adjustment, then there is the high speed and idle adjustment, and lastly the buffer screw.  If you have Jakes, that is another adjustment.  Anyway, if you don't get everything right, you will have low power
  Did I miss the valve and injector height adjustment?? 

--Geoff

[luvrbus]

The DD 2-stoke uses a somewhat complicated governor system.  The governor gap has to be right before you can proceed with the injector rack adjustment, then there is the high speed and idle adjustment, and lastly the buffer screw.  If you have Jakes, that is another adjustment.  Anyway, if you don't get everything right, you will have low power
  Did I miss the valve and injector height adjustment?? 

--Geoff

Or they smoke like a train too

[baker4106]

Guess I did a miracle because mine worked.   Engine ran ok but governor didn't cut in.   I found the gap was too wide and when I got it right I could then adjust the speed.   Didn't affect the engine performace at all.   That was 7 years ago and I didn't touch the rack.

[daddysgirl]

I'm puzzled because a governor on an engine does little more than limit maximum road speed. My bus has the governor set at 56 on the flat. I'm ok with that so I don't see any point in changing it. It makes me slower uphill but that's the only issue and it just plain doesn't bother me.

The governor on the air tank limits pressure to 125psi on most busses with the emergency relief valve releasing at 150psi. Now I'm pretty sure I'd want THAT governor working.


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I apologize for the comment on an older post, but are you are referring to the governor on the air compressor?

And (non-quote specific) I would love to know how anyone with a DD 2 stroke engine governor can get the engine to start and idle without the governor working? It affects everything...at least on my engine. Again, my apologies...SORE subject, but one that sure gave me quite the education.

[baker4106]

Governor doesn't control idle just top end speed.   If you want more ground speed just make sure you don't go over about 2450 rpm.    My 4106 runs just over 80 mph at 2150 rpm.   Ground speed is controled by the rear end gearing.   I owned a 4104 in the 70's that ran the same as my 4106.

[luvrbus]

Governor doesn't control idle just top end speed.   If you want more ground speed just make sure you don't go over about 2450 rpm.    My 4106 runs just over 80 mph at 2150 rpm.   Ground speed is controled by the rear end gearing.   I owned a 4104 in the 70's that ran the same as my 4106.

What controls the idle speed ? if not the governor setting