MEP 831 FAQ for owners or potential buyers

Ha!

When I needed a bowl I paid a LOT more than I thought it was worth but that was pretty much the only viable option I found.

A filter and a bowl is about $50.

Thanks all! I was able to find what I was looking for and I appreciate all the help! Now to put it all together and pray that they both work. If they don't work right I will be on here asking for more help I'm sure.

How important is it to ground the generator if I just plan on using the 3-pin house-hold style plugs? The TM says to drive a grounding rod at least 8 feet into the ground but I'm curious if there are other ways to do this? Any thoughts are much appreciated.

The generator will operate just fine without the ground rod. The purpose of the rod is to provide an opportunity for the unit to ground it's self should there be a short. If the unit (or the device it was feeding) had a short and was not grounded you could become part of the ground path (i.e. Electrocuted). If you are using the unit in the same location repeatedly just beat a ground rod in and then attach a ground cable using a cable clamp. You can find them at any big-box store in the electrical section.

Better safe than sorry I say. I don't want to be part of the ground path

Chris...I read alot of your posts as I am a newbie. I got one of the mep 831 from a guy in Valdosta Georgia and had it shipped up here to Abbotsford BC Canada. At first it would start and then shut down until I learned that you have to lock the mechanical governor on start it. Now it smokes like crazy and I did an oil change/cleaned the oil filter and replaced and still the same...I want to learn so please bare with me...any help you can provide is welcomed. Regards...David

Does it run OK other than smoke? Be sure to carefully check the oil level and make sure its not overfilled.

If you are sure its not overfilled and the oil is OK I would run it more. Place as much load on it as you can and see if the smoking gets worse or better. It should be able to carry 3.5kw without an issue. If not you may need to go into the engine.

Morning!

Chris is right. Run it under load. But start it out at about 1.5 KW, and run it 2-3 hours. Then step it up to 2-2.5 KW. Run it a few hours. Then bump it up to 3-3.5 KW. If you try and start it out at 3-3.5 KW, the gen set may reject the load. Just like you could not run a 30 klick marathon carrying 20 extra pounds, and no training. Got to work up to it!

But he has to lock the throttle to get it to start. Sounds like the the throttle isn't receiving power or it has a fault and wants to shut down. If that's true, then the load test is guaranteed to fail.

If it's smoking, then the engine is either overloaded or it's starved for air. Check the air intake for blockage. I bought a surplus pump and the unit would idle Ok, but would spit and smoke when you tried to rev it up. Couldn't figure out what was wrong so I took to a diesel mechanic. For $55 he removed the storage plug that had been placed in the intake tube.

I need a battery for my mep831a and am unwilling to pay $300 for the original. Thought I saw on this forum that someone had found two 12v batteries that would fit in the stock location. Any thoughts? Regular riding mower batteries seem to be a bit too big...

See if this would work for you.

http://www.steelsoldiers.com/showth...ubleshooting&p=1667559&viewfull=1#post1667559

DieselAddict said:

See if this would work for you.

http://www.steelsoldiers.com/showth...ubleshooting&p=1667559&viewfull=1#post1667559

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Perfect! That's the one I was looking for.. Thanks so much!

Hi, I won 2 Mep831's. One is really sweet and works great. The 2nd one I bought for parts. It only has 22 hours and looks great. It starts and runs well but the governor is way out of wack and there is an oil leak on the engine high up behind the air filter. The speed control is set with the stab,gain and speed at 1:00 and the boost at 11:00. I read on here they should be at 11:00 I think from dieseladdict. I realize I will have to use a Multimeter to set it properly. I have to shut it down by manually increasing the speed and then it will shut down. My question is with the oil leak and governor problem is it worth trying to salvage it? Can the seal be accessed without pulling the engine? Would the oil leak affect the governor operation. Thanks Ted

I'm not sure what would be leaking oil because the only Yanmar that I have which leaks has a crack in the case. That said, Yanmar parts are very cheap so it's worth the effort.

The governor setting is just labor so there no cost, so long as you already have a good multimeter. I had to buy a better one because my cheapie didn't read Hz. I put like 4 hours on the engine fiddling with the settings until I had it right. Unit still wouldn't shut down until I had the target gap set just right.

Any set, So long as the unit makes power and only needs adjusting, would be repairable.

Thanks for the encouragement Cord. I think the leak is from the seal behind the flywheel and the flywheel is throwing it up high and it is dripping down the rubber seal on the cover. Only one way to find out. I already have the recoil off so hopefully I can pull the shield too without removing the engine.
As far as the govenor is concerned it is a mess. The linkage lengths have been changed so they are not even close to the specs. I think I will set the linkage and speed control exactly the same as the machine that runs really well to start and then use my multimeter[ it does measure HZ thankfully] to fine tune it. Again thanks. This is a great Forum.

ted50 said:

As far as the govenor is concerned it is a mess. The linkage lengths have been changed so they are not even close to the specs. I think I will set the linkage and speed control exactly the same as the machine that runs really well to start and then use my multimeter[ it does measure HZ thankfully] to fine tune it. Again thanks. This is a great Forum.

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Mine was screwed up as well. It took a lot of fiddling to get it set just right but it is doable. Once in a while the target doesn't stick upon shut down, but that's just a matter of making a tiny adjustment to the magnet strength.

Cord, I decided to identify the oil leak before spending time on adjustments and your diagnosis was right on. There are 2 cracks in the case on either side at the level of the bolt that holds the lifting cable. I guess I'm back to having a parts machine which is what I bought in the first place. it would have been nice to salvage it but thats life.

Can you pick up a for parts Yanmar L70 off ebay and get it going?

I am going to keep an eye on ebay but this was meant to be a "parts machine". I don't know if I want to buy another parts machine to fix a "parts machine" if you know what I mean. It was just that it started right up and ran so well I hoped I could salvage it.These **** things are addicting. I started out at the start of the summer buying an 803 for home and was so impressed I got a nice 831 plus the 831 parts machine for my cabin. I think I will stick it in the back of the shop and wait for a power outage before trying to fix it then maybe my wife will be more understanding. She has been really supportive so far but I don't want to over do it.

I found one on Ebay Chris. $200 shipping included. It is a complete non running engine. I thought about your advice and since I also need a recoil it was a no brainer. Except for the crack in the block my engine is mint. The recoil packed it in when I forgot to use the decompression lever. I can transfer all of my almost new components and have parts left over for the future. Thanks. Ted