MEP 831 FAQ for owners or potential buyers

[DieselAddict]

This is all great info. Thank you, guys.
I am having a problem with my 831A. The engine is running well. However, it will only charge the lugs in when I activate (Battle Short) and then close the interrupter. If I start the unit and try to set the interrupter without the Battle short on, the lugs will not charge.
Any ideas?

Recommend starting a new thread. It will be better for us to help you.

 

[CommieGIR]

I use a pair of motorcycle batteries in series. A much less expensive solution.

Just want to add this is how I power mine, and its surprisingly happy with pretty small batteries (I had two 6AH 12v Motorcycle batteries) and it cranks happily on them.

 

[AfghanVeteran2010]

While searching NSNs, I ran across this PS magazine article, about muffler mounting hardware. TM 9-6115-639-13&P dated 30 APRIL 2010 correctly reflects the change.

 

[MarauderPPK]

my MEP-831A runs good when it runs, but it has a bad startup issue. Preheating up to 45 seconds didn't make a difference. I was sick about the bad startups and thought the fuel is running backwards. But every manual startup attempt was a very successful attempt with no issues at all so i am wondering more and more... months over months are gone... the comparision to a construction machine's diesel engine or a mower was the forewarding idea: first we open the gas throttle to idle speed, then we crank the engine. The magnetic actuator is held by the magnet to close the throttle to stop the engine. But it is held during startup and after cranking a long minute it release and then the engine can run (!) - what is defective on the controller? Is there a relay contact worn? Or is this a problem of the controller (he must give a current on the coil of the actuator on RUN-Position to immediate release the actuator from the magnet, but it won't work)? When i pull it manually away from the magnet, it starts up on starter position immediately with no issues as like in manual startup procedure. Had you found a healthy solution for this (i don't want to pull the actuator off the magnet manually every startup; because i want to let a plc decide to autostart up and stop the genset).

 

[kloppk]

The 831 SLC100 Governor Controllers (GC) are extremely failure prone. That's why I make and sell a reliable replacement.
When you move S1 from STOP to RUN the GC is supposed to put out a brief pulse of power to the actuator to pop it off the magnet. Very likely it's the GC that failed. Another slim possibility is that someone fiddled with the strength of the magnet and made it too strong.

 

[CallMeColt]

my MEP-831A runs good when it runs, but it has a bad startup issue. Preheating up to 45 seconds didn't make a difference. I was sick about the bad startups and thought the fuel is running backwards. But every manual startup attempt was a very successful attempt with no issues at all so i am wondering more and more... months over months are gone... the comparision to a construction machine's diesel engine or a mower was the forewarding idea: first we open the gas throttle to idle speed, then we crank the engine. The magnetic actuator is held by the magnet to close the throttle to stop the engine. But it is held during startup and after cranking a long minute it release and then the engine can run (!) - what is defective on the controller? Is there a relay contact worn? Or is this a problem of the controller (he must give a current on the coil of the actuator on RUN-Position to immediate release the actuator from the magnet, but it won't work)? When i pull it manually away from the magnet, it starts up on starter position immediately with no issues as like in manual startup procedure. Had you found a healthy solution for this (i don't want to pull the actuator off the magnet manually every startup; because i want to let a plc decide to autostart up and stop the genset).

Get rid of the horrible controller that comes with it, support a great member here, and do the 30 minuet install. You will save yourself a lot of headache.

 

[LuckeyD]

Hi Folks. New to the forum. Hints on the 831; Oil filter is a screen. Pull clean and only replace if it has a hole in it. Safe is pull it every other time. BII includes a 90 degree fitting and hose so you may use to drain oil. Main gen removal: Use a document protector between the rotor and stator so it slides easier. The several hundred i played with I used a screw driver instead of a prybar. Its a finger pincher. Permanent magnet, so you only worry about each of the 5 phases having an output and measurements of about 179VAC ~ to ~ at the A8 are somewhat easy. Once a decision is made I have all you ever need for this one. If not just yell and i can excerpt portions not in the latest 2017 manual but from the Dist Code A 2000 manual. Battery or not: Battery helps, but they come standard with 2 insulated terminals by the battery mount wall you clamp original cables to, and you can pull start it and the A9 don't care. Good Luck with that. Worse than a MEP018 to pull start. Don't for get the compression release, and long pulls, not a jerky one like a lawn mower or chainsaw. Got a parts list from the Dist Code A manual but waiting on a decision to post along with color coded schematic. What to look for in a busted A8. They have their uses. Latest VR adjustments, notes on the relays the works. What usually breaks, stories of what GIs did to them forever, dos and don'ts.