Another MEP-802a post

[JR2980]

Ok - so I learned 2 things this weekend.....

1 - the other genset works, so now I have 2 good gensets. I swapped out the primary fuel pump from the one I knew worked, to the other one, and it fired right up and makes power (tested with the toaster again).

2 - The primary and aux fuel pumps look the same, and even have the same part number stamped on them, but they are not the same. Fittings are different, and not swappable from one to the other.


I just ordered an airtex 8131 and we'll see if that will work. I sure hope it does - I found a place online that sells the facet 24v fuel pump listed for the MEP-802, but they want $250 for it. I got the airtex for $40.


Question I have is, the outlet on both aux and primary pumps is solid steel line, while the inlet is flexible line. Is there a reason for this, or could I swap the solid steel line for flex braided steel fuel line? It would make life easier when it comes time to mount the new airtex pump (assuming it works).

I also looked closer at the radiator, and it turns out that its just painted black, and the paint made it look like plastic - its actually metal, so I may be able to get the radiator overflow braised/soldered easier than I thought.

Last but not least, the "voltage" adjust switch on one of the sets is broken - it spins completely around, and while I was able to adjust it to 120v, the range was very small. The other one works good and the adjustment range was much wider. Does anyone have a part number for this switch? I didn't have time to pull it from the panel and inspect it for a part number. I'm hoping it will be easy to find, but am a little worried - most gensets I've seen don't have a "voltage" adjustment, so I don't guess that its a common part.

 

[m-35tom]

voltage adjustment is just a potentiometer, common for mil sets, rating should be stamped on the back, rad can be easily soldered, fuel pressure is only 4 to 5 psi so most any fuel line would work, just be sure it is a low pressure pump.

 

[kloppk]

The voltage adjust "Switch" (potentiometer) is part number RV4NAYSD502A. It's a 5K ohm 10% 2 watt potentiometer.
You can order them from:
Digikey $8.99 http://www.digikey.com/product-detail/en/RV4NAYSD502A/RV4N502C-ND/222807
Newark Electronics http://www.newark.com/honeywell-s-c...a/potentiometer-cond-plastic-5kohm/dp/01F2643
and probably a number of other places too.

 

[JR2980]

The voltage adjust "Switch" (potentiometer) is part number RV4NAYSD502A. It's a 5K ohm 10% 2 watt potentiometer.
You can order them from:
Digikey $8.99 http://www.digikey.com/product-detail/en/RV4NAYSD502A/RV4N502C-ND/222807
Newark Electronics http://www.newark.com/honeywell-s-c...a/potentiometer-cond-plastic-5kohm/dp/01F2643
and probably a number of other places too.
View attachment 488239

Perfect - thanks!

 

[JR2980]

voltage adjustment is just a potentiometer, common for mil sets, rating should be stamped on the back, rad can be easily soldered, fuel pressure is only 4 to 5 psi so most any fuel line would work, just be sure it is a low pressure pump.

Thanks for the info - the research that I found indicated that the stock pump is rated at 10psi, and the airtex that I ordered is rated at the same, so it should be ok.

Next question is - can I use barb fittings with clamps instead of the crimped fuel line? I'm considering replacing the solid steel line with braided steel hose and would prefer to just buy a reel of it and some barb fittings and build the exact length that I need so that I can route it out of the way and exactly where I want it. It looks like all of the stock hoses have crimped ends - almost like hydraulic hoses - and I want to make sure that the barbed fittings will hold before I buy a roll of braided line and start making my own.


Thanks!

 

[dependable]

I was wondering if anyone else noticed the TB11-6115-741-24 that kloppk recently added to the TM download forum. It has a few upgrades and notices specific to the 802.

Besides a few wiring changes, one to protect VR, it says to use break in oil for the first 100 hrs after motor rebuild.

Looks like mine has been rebuilt and has 9 hrs, the was a detached break in oil tag and a Lister Peter rebuild tag in document pouch. Any one with low hr units using break in oil? Any informed opinion as to its merits?

 

[m-35tom]

john deere has a break in oil. it has high zinc and phosporous, most sites say not to use synthetic but amsoil says to use theirs so who knows!! the issue is having good enough lube for rings and flat tappet cams until everything is worn in. i would find a oil that says it is a break in oil.

 

[steelypip]

Break in oils also sometimes are chosen for reduced lubricity relative to running oils. Using too-good (too strong a film) oil during break in can result in glazed bores because the film strength is so strong that the rings don't continuously contact the bores and bed in. In combination with a booster package of zinc and phosphorus (the generic favorite in the hot rod world is GM EOS), you have an oil that isn't too good to bed the rings but still has a lot of friction reducers to prevent wiping the cam in sliding metal-on-metal contact.

Usually, break in oil often just means to use a simple petroleum base oil (often of lower running viscosity) for a short break-in period and then switch to a better oil for running. The final arbiter would be Lister-Petter, as they designed the engine.

 

[JR2980]

Just wanted to post a little info that I came across yesterday.

I picked up a MEP-501a genset from the NG armory and had a few minutes to talk to the genset mechanic - we got to talking about the 80x series of gensets, and he said that a lot of the ones sold down at Ft Meade had come from them.

He said that the generators were beasts and would run at 115% of rated power for months on end with only routine maintenance - he said he personally maintained several in the sandbox that were running at 115% non-stop for months with no issues.

Biggest issue that he said you'd run into is the little aux parts (fuel pump, switches, etc) - easily replaceable stuff, but the engines would run for ever no matter how they were abused.

I mentioned that several had gotten water in the exhaust and destroyed the engines - he just laughed and said that happens a lot and the engines were fine, just drain the water fill with clean oil and start the engine up and it would run just fine.



Now - take all of that with a grain of salt.....if they blow up a genset, they just order up a new one, easy as pie - I sure cant do that. I wouldn't be that cavalier with my 802's, but its good to know that they can take that much of a beating.


He also said that they were sending down some "B" models soon........ wonder how much those will go for!

 

[Ratch]

I just load tested mine the other night.
I have to get an ammeter on it or an ohmmeter on my element, but with a 4500 watt water heater element, it started at 40%, then went down to 25% as it heated up. I tacked on a second element just for the heck of it, and she bogged right down and struggled to run. What I figure is that the first element is pretty old and actually operating at 1250 watts (25% of 5kw), and the other is operating at closer to the proper 4500 watts. 4500 + 1250 = 5750 watts.

5750 is 115% of 5000. Mine couldn't handle it if that's what it actually works out to.

Of course, I could have an inaccurate load meter, and was actually loading the thing with 9 kw...

 

[JR2980]

I just load tested mine the other night.
I have to get an ammeter on it or an ohmmeter on my element, but with a 4500 watt water heater element, it started at 40%, then went down to 25% as it heated up. I tacked on a second element just for the heck of it, and she bogged right down and struggled to run. What I figure is that the first element is pretty old and actually operating at 1250 watts (25% of 5kw), and the other is operating at closer to the proper 4500 watts. 4500 + 1250 = 5750 watts.

5750 is 115% of 5000. Mine couldn't handle it if that's what it actually works out to.

Of course, I could have an inaccurate load meter, and was actually loading the thing with 9 kw...

I just got a new current clamp meter yesterday - first chance I get, I'm gonna get out and load test mine, then we can compare numbers.



Thanks!

 

[Glockfan]

I just got a new current clamp meter yesterday - first chance I get, I'm gonna get out and load test mine, then we can compare numbers.



Thanks!

I'd be interested in your test results... When I was in Kuwait, we would shut these TQG's down for 10 minutes per month just to change the oil and blow out the air filters... They would run for six months straight in the desert heat and never miss a lick!