MEP 831 FAQ for owners or potential buyers

[DieselAddict]

Great Ted, Let us know how it turns out.

 

[ted50]

Hi Just an update, I removed the flywheel to get a better look at the crack and it was obvious the rear seal was defective. The lips were inverted and I could rotate it wth a screwdriver and was able to lever it out. My mechanic buddy says a new seal would fix it but if I insist on being anal I could tig weld the cracks. I need some advice. The cracks are high up by the front lifting cable and near the rear upper starter motor bolt. What would you experienced guys advise? I bought a "not able to crank"Yanmar L70 on Ebay for next to nothing but would prefer not dismantling everything to switch the block.

 

[DieselAddict]

Its hard to tell how severe those are. My gut is that they aren't terminal.

Do you have the stuff to do a dye test? To see if there are other micro cracks.

 

[ted50]

Its hard to tell how severe those are. My gut is that they aren't terminal.

Do you have the stuff to do a dye test? To see if there are other micro cracks.

No I don't. What would I need?

 

[ted50]

The cracks aren't evident on the backside of the casting.

 

[DieselAddict]

Take a look at this:

https://en.wikipedia.org/wiki/Dye_penetrant_inspection

See if you mechanic had a dye kit. If not you can get it pretty reasonably online.

Its good that the cracks don't appear to go all the way though. A dye test will let you see cracks that are coming that you can't see with the naked eye.

Alternately if the engine is out of the generator you can run it over to a machine shop and they can check it for you.

 

[Cord]

If you're gonna try welding it, I'd suggest v'ing out the crack and drilling a hole at the end of the crack to help stop it's progression. Make sure you wipe it down really well with brake cleaner so you get all the oil off the surface and out of the crack. I have a Yanmar in a compactor that's leaking oil from a crack. Tried sealing it up with epoxy and it lasted a good 5 minutes before I saw the oil seeping out. If you have success welding your crack I might try mine. Honestly I'm figuring I'll be buying a new housing.

 

[Guyfang]

Dye kit is cheap and fool proof. Well worth the money after using it one time, and finding that I did not have to order another part!

 

[ted50]

Well, today started out not so well. Picked up my Ebay engine and it looked like it had been dropped off an apartment building. Starter solenoid broken off, preheat casting broken and the air filter housing was crunched. I looked at the block casting and it had the same darn crack where the lifting bolt attached. The engine was seized. So I looked behind the flywheel and there was a massive mud nest with larvae glueing the flywheel to the engine casting. I am used to small mud wasp nests, I have never seen anything like this. The holes for the larvae were huge. I will enclose a photo of a small potion of what came out. I broke it up as best I could and the shaft turned OK.
My mechanic buddy arrived and we took the engine with the crack to his machinist friend to weld it. His frlend looked at it and got a big grin on his face and asked if i really wanted him to weld a casting seam. He said take it home sand it off and see if there is a crack. He was right. Humbling experience. The good news is I only have to put an $8 dollar seal in an engine with 22 hours on it.
I really appreciate all the advice on this forum. The information from smart experienced guys has been so helpfull!!
On another topic I bought 2 slave plugs that were previously used to power impact wrenches. The Noco 7200 Genius ring accessory cables fit the internal connectors exactly. Photo enclosed

 

[ted50]

So, I now have a spare Ebay engine that is pretty banged up. The seller looks like he is willing to compromise. Thankfully the main part I needed[ the recoil] is functional.

 

[ted50]

Hi, I installed a new seal and the engine runs really well, no leaks. I still have major governor problems but that is for another day, probably on troubleshooting. I just want to thank you for all your input. I don't have a mechanical background and it is awesome to be able access experts who are willing to reply even to dumb rookie questions. When I was doing my 803a the same names came up and I learned so much just from reading the forums. The TM's from Guyfang are so useful and the advice from Cord and Dieseladdict plus Guyfang helped so much. Thanks guys!!

 

[DieselAddict]

The governors on those are problematic. Read the docs and let us know how its going.

 

[Guyfang]

The only dumb question, is the question not asked. You are not a dumb rookie. You asked. You learned. Your are better for it. Life is good!

 

[Cord]

I still have major governor problems but that is for another day, probably on troubleshooting.

There is a disproportional number of these units with governor problems. Thankfully the majority just need adjustment. Start by follow the procedure in the TM to adjust the pot switches. Do this several times because subsequent adjustments will throw off the earlier ones. If you still can't get the governor adjusted or can't get the unit to shut down, then adjust the magnet. It's a pia to keep adjusting things, but given time you'll get it.

Thanks for the kind words. Now you are bound to take what you have learned and pay it forward for the next generation to learn by.

 

[Guyfang]

Amen Brother!

 

[paraclete comes]

Ive got to get mine tuned up, running rough and leaking oil. Been so wrapped up with other project, this needs to happen in the next few months. Thanks for all the great input guys, I will be putting it to good use soon.

 

[Guyfang]

Good luck partner! Keep us updated.

 

[Hammond Charlie]

New kid on the block here....

Read thru majority of post on MEP 831A... informative.

Bought 3 units, one parts, two appear to function well, except for one of the two. The Governor appears to make unit surge. Upon start up it would run well for 3 minutes +/- then surge.

Opened up the magnetic governor, rotated arm back & forth to its stops, re assembled, appeared to work fine first cycle thru, restarted and 3 minutes +/- back to surging.

Found the Mtc manual, at 4-14 and 4-13.. any other references? Seems like these are extremely durable units, any elementary oh, I should have done "x" to address this earlier? Thanks.

 

[DieselAddict]

If it goes from stable to unstable with no other changes that is a classic symptom of a failing governor module.

 

[Hammond Charlie]

If it goes from stable to unstable with no other changes that is a classic symptom of a failing governor module.

Diesel Addict... thanks for the prompt reply. Thought about swapping out one from the unit which runs, but not generates... are parts readily available? Can one order a governor?

BTW read thru this board, the magnet can be adjustable.