Picked up 6 MEP-802A gensets and will be documenting making them all runners here

[Ray70]

On the fuel level sensor you are correct, polarity doesn't matter. I usually connect black to what used to be the ground and the sense wire to the red / brown lead, but really doesn't matter and really no point in attaching to one of the mounting screws, I usually just connect with adhesive lined heat shrink butt connectors.

 

[Guyfang]

The parts for the secondary fuel filter finally showed up today, so I was able to go back to working on the 2006 unit. I know I need to pop the head on the 2007, but I'll save that work for a rainy day.

After getting the filter installed, I tried priming, but the fuel pump (old square style), just made a faint humming sound. Undid the suction side and tried blowing into the line going to the tank. Was completely clogged. Using compressed air, I cleared the blockage. While I had the line off, I dripped a little diesel into the inlet of the pump. It still just gave a faint hum. Tapped on the side of it, and little by little it got louder until all of a sudden it started pumping. (This is a very well know problem. You have not fixed it. Just prolonged it to the day the lights go out. Get a new pump. )

I then reconnected the line from the tank and let it run for 5+ minutes to get the fuel circulate real good. I then tried to crank it. Nothing. I heard a click coming from the control box, but the main solenoid on the starter never engaged. Put a voltmeter on the solenoid and it never goes to 24V when trying to crank. Same deal using the dead crank switch.

So I guess the relay that controls the starter solenoid needs to have its contacts cleaned? Need to study the starter circuit diagram to diagnose further.
( Apply 24VDC to wire # 114C on the S10-1. That goes right to the K2-X1. If the motor will not turn over, time to look at K2. Remove X1 & X2 wires from the K2 and apply 24VDC to those terminals. That way you have both + & -. )

Also also got in some fuel senders today. The 5.5" ones. Am I correct that it doesn't matter how I connect the red and black wires since it is just a resistor and the whole thing is floating being a plastic fuel tank? Or should I slip the one eyelet under one of the screws and tie the black wire from the sensor to it?

Open to read comments. Your hot tonight Ray!

 

[pclausen]

I took a look at the circuitry around the starter solenoid and dead crank switch. I do get 24V at the X1 terminal of the K2 relay when applying the dead crank switch or moving the main switch to START.



So I pulled out the K2 relay. Its buried in there below all those main power wires:



After removing those, I was able to get to it:



The coil measured about 120 ohms, so that's not the problem. Removed the "hat":



And separated the coil and plunger from the top piece:



Plunger is rusted solid to the bushing piece or whatever it is.

I'm not having too much luck Googling/eBay'ing an Eaton FSCM 81640 relay.

Any good leads on where to pick one up? Maybe a replacement unit with similar specs?

I checked the Filters & Parts thread, but didn't see anything about the K2 relay.

 

[DieselAddict]

That is a 100 amp rated relay with a 24v coil. Should be able to cross that over to something else that will fit. I did find a couple but they are over $250.

 

[pclausen]

I guess $60 shipped is fair. For right now, however, I'm going to steal the K2 relay from my parts 802 set. I also went ahead and dropped that rusted K2 in a cup of Evapo-Rust. You never know...

 

[DieselAddict]

That looks like it. Does the relay you have indicate it’s 50 amp or 100 amp? When I look at the part number the references I see indicate 100 amp.

 

[pclausen]

Mine says 50 amp.

 

[DieselAddict]

Then I think you found it. The more I look I see references to 100 amp and 50 amp under the same part number. lets see if I can remember that it’s a 50 amp.

 

[Guyfang]

Whats the NSN for the relay? Then I should be able to tell you what the rating is.

 

[pclausen]

NSN 5945-01-365-9953

MEP802A - MEP803A - Many Other Military Generators NSN 5945-01-365-9953, SM50D8, 88-21082 Electromagnetic Relay ⋆ Green Mountain Generators

MEP802A – MEP803A – Many Other Military Generators NSN 5945-01-365-9953, SM50D8, 88-21082 Electromagnetic Relay. This is a functional equivalent for these NSN and Eaton product numbers. Overall Length: 2.750 Inches Maximum Center To Center Distance Between Mounting Facilities Parallel To Length...

greenmountaingenerators.com

 

[kloppk]

Search MS24166-D1 on ebay. Lots of listings

 

[Guyfang]

	OVERALL LENGTH	2 3/4 INCHES MAXIMUM
	CENTER TO CENTER DISTANCE BETWEEN MOUNTING FACILITIES PARALLEL TO LENGTH	2 9/50 INCHES NOMINAL SINGLE MOUNTING FACILITY
	OVERALL HEIGHT	2 5/8 INCHES MAXIMUM
	OVERALL WIDTH	2 1/8 INCHES MAXIMUM
	UNTHREADED MOUNTING HOLE DIAMETER	0 219/1000 INCHES NOMINAL SINGLE MOUNTING FACILITY
	WINDING QUANTITY	1
	COIL QUANTITY	1
	WINDING DC RESISTANCE RATING	94 OHMS NOMINAL SINGLE WINDING
	DUTY TYPE	CONTINUOUS
	MOUNTING FACILITY TYPE AND QUANTITY	2 UNTHREADED HOLE SINGLE MOUNTING FACILITY
	MOUNTING FACILITY PATTERN	IN-LINE SINGLE MOUNTING FACILITY
	NONPILE-UP MAIN CONTACT ARRANGEMENT	1 POLE, SINGLE THROW, NORMALLY OPEN, DOUBLE MAKE, MOMENTARY ACTION
	OPERATING VOLTAGE RATING AND TYPE AT SPECIFIED TEMP	28 VOLTS DC 25 DEG CELSIUS SINGLE WINDING
	MAIN CONTACT LOAD CURRENT RATING AT MAXIMUM RATED VOLTAGE	50 AMPERES DC RESISTIVE LOAD
	MAIN CONTACT MAXIMUM VOLTAGE RATING IN VOLTS	28 DC
	TERMINAL TYPE AND QUANTITY	4 SCREW ALL FUNCTIONS

This part is in a million different pieces of equipment.

 

[pclausen]

Thanks for the info and links!

I did steal the K2 relay from the parts set and installed it in the 2006 unit. That did the trick and I was able to crank it over. On the 2nd attempt it started to fire, but I shut it down right away since I haven't added any coolant yet, but that's next!

 

[pclausen]

I filled the coolant system with water and I had a leak at the thermostat housing using the OEM gasket. Drained the system, removed the intake and muffler and upper radiator hose and took the housing apart. I then cleaned it up as best I could:



The new water pump was machined pretty rough, so my guess is what's why it leaked.

Housing:



I'm trying this stuff this time:



Laid down a bead and put things together finger tight. Came back an hour later and torqued down to spec and will let it sit 24 hours per the directions.

I ended up just soldering and heat shrinking the new fuel sensor:



Figure that sensor will last many thousand of hours before failing.

 

[pclausen]

Refilled the cooling system on the 2006 with water and I have no leaks. So I proceeded to crank and start it. Here's a video from that initial start:

Something seems "off". I think the RPMs are too high, but my instrument panel is completely dead, so I'm flying blind. I let it run for about 10 minutes until both the upper and lower radiator hoses were warm to the touch. You will notice in the video how the whole set seems to be swaying a little side to side.

I let it sit for a few minutes, reduced the RPMs a bit via the frequency adjuster and started it again:

With the reduced RPMs, the swaying seems to be gone, but it still seems off balance. It is almost as if its running on one cylinder.

I'll see if I can find my infrared thermometer and shoot both the front and back of the exhaust manifold to see if there is a significant temperature difference.

 

[DieselAddict]

In case you'd like a reference for a good running 802. I just went over and shot this video of the one I have at the off grid property. This unit was recently load banked at 125% and did great.

 

[pclausen]

Thanks for that. Definitely starts a lot smoother than mine. Kind of hard to make out the rpms from the audio alone, but I think mine is in the ballpark.

I started checking voltages on the "I" terminals on my engine gauges. They are all around 7.8 volts instead of 24 volts. So I'll chase that down first. Probably a loose/bad ground somewhere.

 

[DieselAddict]

Telephones can't capture those kinds of sounds well. The machines are coming together!

 

[pclausen]

They are indeed! After a 7 year hiatus.

So I got the low voltage at the "I" terminals sorted out. The 24V feeder from #3 on the S1 master switch was wired to the S terminal on M5 (fuel level indicator) and that was pulling down the voltages on the other "I" terminals, since they are all wired together.

Unfortunately, all 3 engine indicators are shot, so those will need to be replaced. I kind of knew this already since I had tested them before, but now that the engine is alive, I need to do something about it. I have several dead ones in some of the other sets, but I do have 2 working sets I believe. Not too worried about that right now. I want to get the frequency meter going first so that I can set the engine to 1,800 rpm.

Need to look into testing all four of the remaining indicators I suppose. I'll research the process for that next, or just follow the troubleshooting steps in the TM, and go through table 2.6 in 9-6115-641-24, one line item at a time.

Unfortunately the wife made it very clear that I'm not to start the generator again in the garage tonight (garage is attached to the house and in close proximity to the kitchen.) I will admit starting it for the first time inside the garage was not the best idea. There is now a nice crunching sound walking on the floor from all the tiny rust particles that were blown out of the muffler on that first start.

Hopefully spring is right around the corner and I can move my operation back down to the shop building where it belongs. The 1.5 car garage is pretty cramped to work in, especially with 3 sets sitting on the floor.

 

[Guyfang]

Thanks for that. Definitely starts a lot smoother than mine. Kind of hard to make out the rpms from the audio alone, but I think mine is in the ballpark.

I started checking voltages on the "I" terminals on my engine gauges. They are all around 7.8 volts instead of 24 volts. So I'll chase that down first. Probably a loose/bad ground somewhere.

Lets keep things in prospective here. The 802A is a shaker, from the get go. Much rougher then the 803A. It is a 2 jug machine. You have it torn apart, denying it any chance to not sway, and shake even more then it normally will. If you run it long and hard in this condition, do not act surprised if something falls off. Give it a break. If it walks across the floor, you need to look into that. But from what I saw, its not all that bad.