MEP 831A Fix-up Thread

[CallMeColt]

Everyone,

Yesterday, I picked up a MEP 831A generator set for $400. Has a little enclosure damage. The upper fan unit was missing. Pull start was removed due to the rope breaking. The positive wire side for the battery was cut. Solar charger wires & the upper fan wires were cut. Moved it by hand where the pull start would be at it build compression. Besides these issues & being real dirty from sitting in a field, it seems complete. Has 900 hours on the clock. Fuel was drained as best as it could be. There is fresh oil in the engine. The person I got it from said that they got 8 of them at auction years ago. He started it & just plugged in a light & shop fan then let it sit after draining the fuel.

I started by just collecting all the bolts & parts sitting at the bottom of the enclosure. Vacuumed out what I could of the dust & spider webs. Hooked the locking arms for the cover back up. Rinsed down with a hose.

Downloaded the TM's & other manuals available here on the forums. Confident it should start once I get fluids in it & jump it with my larger MEP 802A.

 

[kloppk]

Congrats!
The pictures aren't the best resolution so it's a bit hard to make things out.
I looks like that one of the mechanical governor adjustment bolts may be missing.

 

[CallMeColt]

Congrats!
The pictures aren't the best resolution so it's a bit hard to make things out.
I looks like that one of the mechanical governor adjustment bolts may be missing.


View attachment 774306

Very possible. I have never had one of these. There were a few bolts sitting at the bottom. I will see if one fits in where you have pointed out.

EDIT - The knob was tightened to hold the throttle in place. No screws are present where you pointed out.

 

[CallMeColt]

Well, I made sure the oil & fuel was filled up. Cut back the battery wires a little but to be sure they were clean. Went to jump from my MEP 802A & nothing. Made sure there was correct voltage at where the jumper cables were connected. Made sure the emergency stop was pulled out. No fuses blown. Was really hoping for it to just turn over & fire up! There doesn't seem to be any power at all to anything.

Time to do some reading. Hopefully it's something stupid.

 

[CallMeColt]

Alright, so I went through the field level troubleshooting of TM-9-6115-639-13&P, page 124-125 on the .PDF file. While doing so, it dawned on me that the main DC circuit breaker wasn't staying in. I quickly went & looked a similar type breaker in my MEP-802A & realized that it definitely was bad. After realizing that, I put a jumper on it... & got power. Started it up to find a fuel leak from the fuel filter. Bypassed that & started again. Messed with the manual throttle & let it run for a few minuets. Hit the emergency stop & it kept running so I pressed the decompression lever. The linkage for the throttle or whatever it is (please see picture with me pointing to it) had popped out of place. I guess this is how it is shut down.

I was able to observe the voltage meter & it was able to be adjusted to 240 volts. I didn't hook up to see if it was at 60hz but my guess is that it was considering there was no load & it is an inverter. With load, it may have dropped since the throttle controller wasn't connected properly.

Anyways, with all this, it tells me that the important stuff is working & the generator is worth putting time & money into. Going to get some batteries & a pull start. Going to dig in to find that DC breaker. I know the fuel filter part numbers are in the forums here so I will find those as well.

Need to remove some of the panels to get at some of the spots that are dirty to clean the inside. There's enough where it makes me worried about a fire if it were to run for a while.

My wife saw sparking & I noticed it in a video that she recorded. It's posted below.

Also included a picture of the hardware I found in the bottom of the enclosure. One of them is the mechanical governor adjustment bolt. Hose clamps were for the removed oil drain hose. Two smaller bolts are 2 of the many from the removed pull start assembly.

Anyways, I'm pretty happy so far. At minimum, I have a good Yanmar engine! At most, I will have a great unit that just needs tome time & money.




https://www.youtube.com/watch?v=Ro95Kw64qRQ

 

[CallMeColt]

Ordered the breaker, pull start assembly, & two AMG sealed ATV batteries just now. Once I have everything I will share part numbers & sources. Going to stop in & get the WIX fuel/water separator tomorrow at O'Riley's.

This should get me going pretty good. Then I will just need to get that throttle control squared away. Did a little digging here on the forums & found that it should be set 5/16 inch away from the magnet with no load. ~ 1 inch away when it is off. Going to start with that once it is running with an easy start & no fuel leaks. Also need to look into how to properly adjust the mechanical governor.

Need to pull the access panel off the rear so clean out the stuff that's stuck in the rear vent... fire hazard!

 

[CallMeColt]

Over the past few days, I cleaned it up a bit more. Opened up a few of the panels to get all the leaves & stuff out that were stuck in there.

Still waiting on a lot of the parts. I did get the two batteries & they will fit no problem. To make them easier to handle, I duct taped them together real well. Ordered a universal rubber batter holder/tie down.

The eBay recoil start assembly I ordered came in. Built well but it didn't fit into the cup part that attaches to the engine crank shaft itself. Returning it to order from another seller that has the cup included as well. Old one is on top.



Was able to find the part that the rope goes through the enclosure. Probable could have just made something but it wasn't a terrible price so I just got it.

Did a LOT more reading on the site here. Confident I will be able to get everything adjusted for the governor. If it gives me major problems after going through the adjustments, I'm just going to get kloppk's.

Did find the mechanical governor screw & nut in the bottom. Put it in place but I'm not sure how to adjust all that yet. I'm sure it's in the TM.

 

[kloppk]

...Did find the mechanical governor screw & nut in the bottom. Put it in place but I'm not sure how to adjust all that yet. I'm sure it's in the TM.

You won't find that adjustment in the TM. It's factory set and is secured in place with a safety wire and lead seal at the factory.

So for a starting point for that adjustment I took measurements of that adjuster on my two 831's.
The adjusters height from the plate to the top of the bolts were 0.793" and the other 0.765"

You may want to try an initial setting in that range.

 

[CallMeColt]

You won't find that adjustment in the TM. It's factory set and is secured in place with a safety wire and lead seal at the factory.

So for a starting point for that adjustment I took measurements of that adjuster on my two 831's.
The adjusters height from the plate to the top of the bolts were 0.793" and the other 0.765"

You may want to try an initial setting in that range.

Thank you very much for in information. Can you send me a picture of yours? There are two holes that it can go in & I want to be sure I'm setting it in the right one. Also, I'd like to see how the wire is on there & where your manual throttle knob is set too. Possibly could do something similar once I get it right.

 

[CallMeColt]

So, taking a break from working on it right now & solved a few problems.

Spark at the starter was due to a missing nut! Can't believe I didn't notice that. I need to figure that thread pitch out now...

Put the new breaker in. Put the new fuel filter in. Used some temporary cables & fired her up. Put an outlet on & ran ~3,000 watts on it. Ramps up & down beautifully! The only issue is the shut down... tried & then gets stuck in the low idle. But, I think the mechanical adjustments with the governor are the problem. Also, I'm going to use some break clean & clean up the magnet & target. Very dirty/greasy. Going to go via what the TM says for the linkage & off of what kloppk shared above for a measurement.

 

[kloppk]

... Can you send me a picture of yours? There are two holes that it can go in & I want to be sure I'm setting it in the right one. Also, I'd like to see how the wire is on there & where your manual throttle knob is set too. Possibly could do something similar once I get it right..

Here is a pic of one of them.

 

[CallMeColt]

Here is a pic of one of them.

This is great, thank you!!

 

[CallMeColt]

Using the information I got from kloppk above & using the TM for the adjustment procedures, I got it pretty darn good. Starts, ramps up slowly when full load is applied, & shuts off. The only issue I'm having now is that the rod is lifting out of the hole it's supposed to go in ever so slowly when under full load. I'm thinking it is the mechanical governor that needs to be tweaked. Had to stop for now since I had a rough day at work & then crouching over this generator for a few hours really has me soar. But, I'm very happy that I have a working controller & everything seems good. Just needs to be tweaked.

Got a dripping leak from the fuel filter. I believe it is the gaskets on the bowl. Hopefully, I can source just those somewhere.

Also noticed the fuel gauge & hour meter don't work. Honestly don't care about those right now but I will correct them at some point.

 

[CallMeColt]

So, I have searched high & low through the internet with no luck finding two parts that I'd like to get... the LED light for the circuit interrupter & the top vent fan. I used the TM to get proper part numbers & did NSN & manufacturer part number searches. I think I need to find someone who has a parts machine for me to get them. Anyone know where there might be one?

 

[kloppk]

The fan is a Rotron part number 031842.
They are on ebay for $25.
Also available on DigiKey and Allied Electric.

The Contactor lamp is an incandescent bulb, not an LED.
** edit, it can be an LED or Incandescent

 

[CallMeColt]

The fan is a Rotron part number 031842.
They are on ebay for $25.
Also available on DigiKey and Allied Electric.

Man, your the best! I think what I did was copy/past the incorrect part number from the TM when I searched.

The eBay listing doesn't seem to have wires or anything but I'm sure I can follow to TM & make it work.

 

[kloppk]

The fan doesn't have wires. It has two metal tabs the fan power cord slips onto.

I'm looking for a replacement lamp for you...

 

[CallMeColt]

The Contactor lamp is an incandescent bulb, not an LED.

The TM says it is an LED... doesn't mean it is.
98-19763 . LIGHT, LED INDICATOR

 

[kloppk]

Ahhh... You're looking at the 2010 TM, I was looking at the 2005 TM.
You are correct they call out a LED lamp in the 2010 version.
The PN 98-19763 cross references to a Dialight PN 586-1102-005F.
That bulbs spec are: T1 3/4 base, 28 V, Green, 520 nm Wavelength, 600 mcd brightness
Looks like that version is obsolete.

There is a suitable replacement that is readily available.
It's the Dialight PN 586-1102-105F (5861102105F)
That bulbs spec are: T1 3/4 base, 28 V, Green, 520 nm Wavelength, 600 mcd brightness.
For about $6 they are available at:
https://www.digikey.com/product-detail/en/dialight/5861102105F/350-2139-ND/1693272
https://www.newark.com/dialight/586-1102-105f/led-bulb-midget-flange-green-t/dp/33M4496
https://www.mouser.com/ProductDetai...7tGLUz3AkL6jqLxsuKl9qkqg3zonL3LxoCr-IQAvD_BwE

 

[CallMeColt]

Ahhh... You're looking at the 2010 TM, I was looking at the 2005 TM.
You are correct they call out a LED lamp in the 2010 version.
The PN 98-19763 cross references to a Dialight PN 586-1102-005F.
That bulbs spec are: T1 3/4 base, 28 V, Green, 520 nm Wavelength, 600 mcd brightness
Looks like that version is obsolete.

There is a suitable replacement that is readily available.
It's the Dialight PN 586-1102-105F (5861102105F)
That bulbs spec are: T1 3/4 base, 28 V, Green, 520 nm Wavelength, 600 mcd brightness.
For about $6 they are available at:
https://www.digikey.com/product-detail/en/dialight/5861102105F/350-2139-ND/1693272
https://www.newark.com/dialight/586-1102-105f/led-bulb-midget-flange-green-t/dp/33M4496
https://www.mouser.com/ProductDetai...7tGLUz3AkL6jqLxsuKl9qkqg3zonL3LxoCr-IQAvD_BwE

You're real good at this!

Bulb definitely looks like it will work. The issue now if finding the cover that screws on. The TM doesn't even have that listed as a part. Maybe I need to buy just the whole assembly?

I found a listing on eBay for a take off yellow combat short from an MEP 803A. It's like $25. Besides being yellow, it has everything.