Obscure question, MEP-831A

[Fungal]

Does anybody know (because I can't find this documented in the manuals, all of which I have hard-copies of) the actual SIZE of the oil-drain-plug mounted in the side of the skid?

I haven't lost the plug or anything like that, but what I really want is a hose-adapter for that port... because I'm just tired of oil running down the side of that skid and dripping all over the garage floor.

 

[Light in the Dark]

I assume the baby MEP has NPT threads like its bigger brothers, so just pull the plug and head over to a hardware or plumbing supply shop and match up with some fittings. Seems the 831 doesnt have a proper -24P for the machine (I saw one for the engine in the TM section here, but not for the whole machine).

I think I sourced a 1/2-14 air hose adapter with straight threads that worked fine on my 802. Going off memory here. Does the 831 plug accept a 3/8" socket square shaft to loosen?

 

[Guyfang]

Tech Info

	THREAD CLASS	2A 1ST END BULKHEAD
	CONNECTION STYLE	PLAIN (PIPE) ALL ENDS
	CONNECTION TYPE	THREADED INTERNAL PIPE ALL ENDS
	NOMINAL THREAD SIZE	0 3/8 INCHES ALL ENDS
	NOMINAL THREAD SIZE	1 INCHES 1ST END BULKHEAD
	NOMINAL OVERALL LENGTH	1 39/125 INCHES
	MATERIAL	STEEL OVERALL
	STYLE DESIGNATOR	THREADED INTERNAL
	THREAD SERIES DESIGNATOR	NPT ALL ENDS
	THREAD SERIES DESIGNATOR	UNF 1ST END BULKHEAD
	FURNISHED ITEMS AND QUANTITY	1 BULKHEAD NUT

 

[Ray70]

In simple terms, the thread is a 3/8" NPT pipe thread.
If you mean it drips and makes a mess when you change the oil, a simple solution is to just screw in a 6" long piece of 3/8" black iron pipe, heat up the engine, drain the oil, remove the pipe and stick the plug back in.

 

[Fungal]

In simple terms, the thread is a 3/8" NPT pipe thread.
If you mean it drips and makes a mess when you change the oil, a simple solution is to just screw in a 6" long piece of 3/8" black iron pipe, heat up the engine, drain the oil, remove the pipe and stick the plug back in.

And that's exactly what I was planning to do.

Thank you all for the information

 

[Fungal]

Got a short piece of stainless steel pipe, and it fits the oil port perfectly. Problem solved.

New problem tho… I tried to start it last week with a couple of UPS batteries in series. Got the fuel pump to run, but it wouldn’t turn over.

I figured the batteries were too small, and/or didn’t deliver enough amperage… so I got two powersports batteries (about 300CCA each), put them in series, and tried to hook up the generator. Holy Arc-Flash, Batman… melted the terminal on one of the batteries trying to hook them up.

The connections are right, polarity is correct, as is the voltage, but something is shorted in the genset. I can’t even hook the batteries up without a shower of sparks.

I’m wondering if the solenoid is bad/stuck.

 

[Ray70]

Definitely sounds like the starter solenoid is stuck or you have a wire backwards.
I've been using the small 12V 21AH batteries in my 831, my 4 wheelers and my son's LPW2 powered tractor all with no issues.
They're cheap and I can lay them on their side in the tractor with no issues.
I'd disconnect your starter wire and see if that stops the flaming arc show when you hook up the batteries.
If so trace backwards through the start circuit until you find the problem.... probably the solenoid.

 

[Ray70]

Based on your first post I am going on the assumption that you've had this gen for a while and it's been working correctly until now, right?
And all you did was add the oil drain extension and some new batteries??

 

[Fungal]

No… this genset is new to me. Reportedly ran before it went into storage. Last serviced in 2021. It’s not seized-up or anything of the sort. I’ve owned a bunch of generators over the years (mostly Kohler and Honda), but this is my first of this sort.

I’ve already done all the usual stuff. Replaced all filters, changed the oil, etc.

Whatever it wrong, something is drawing a LOT of amps when I try to hook up the batteries, and they’re definitely hooked up correctly. Next step is obviously to check that solenoid, and if it’s dodgy in any way, I’ll just replace it (probably should anyway, just on general principle)

It’s on the back side of the engine… so I suspect you have to remove the exhaust to get to it?

 

[Light in the Dark]

Edit... I thought you were talking about an 803, sorry. Nevermind.

 

[kloppk]

...It’s on the back side of the engine… so I suspect you have to remove the exhaust to get to it?

No need to pull the exhaust. Just unhook the wires going to it.
Then remove the two bolts securing the starter to the engine and remove the starter.

There is also relay K2 involved with the starter operation.

 

[Fungal]

Where are you gentlemen getting your Yanmar engine parts? Who is the best online source to deal with?

Got the solenoid out... need to source a new one.

 

[DD58]

Where are you gentlemen getting your Yanmar engine parts? Who is the best online source to deal with?

Got the solenoid out... need to source a new one.

I was able to get parts from fleebay, my local Yanmar dealer and some of the guys from here.


Sent from my iPhone using Tapatalk

 

[Fungal]

I was able to get parts from fleebay, my local Yanmar dealer and some of the guys from here.


Sent from my iPhone using Tapatalk

Not sure how I didn't think to check Ebay, but my first hit turned up exactly what I needed.

Gracias.

 

[DD58]

Glad to be of assistance post some pics once you get a chance


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[Fungal]

Well... that was interesting.

I changed out the solenoid, and hooked everything back up... no arcing or shower-of-sparks this time... so that's an improvement.

But I thought I smelled smoke, so I turned it to run with the intention to start it, and smoke began pouring out of the starter. I quickly disconnected the batteries.

So it looks like I need a new starter.

 

[kloppk]

There are a few new ones on ebay for $75 to $100

 

[Guyfang]

If I were you, I might sit down with the wire diagrams, and check every wire on that set. Starters do not normally burn up cause its Wednesday. You might have a wire worn through someplace, or something is miss wired. So before you through any more parts at it, take some time to look real close at the set.

 

[Fungal]

There are a few new ones on ebay for $75 to $100

Which ones are you seeing? The ones I see don't look like they'll fit the genset: they're all 12V

114362-77010 is the part number I searched for.

Also tried S114-414A, but all of those I've found are also 12V

 

[DD58]

Which ones are you seeing? The ones I see don't look like they'll fit the genset: they're all 12V

114362-77010 is the part number I searched for.

Also tried S114-414A, but all of those I've found are also 12V

364635653813 this is the eBay listing number I have been watching.


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