MEP-701A generator questions

[TaylorTradingCo]

I am thinking of buying a MEP-701A generator. I have some questions about them though.

Do all of them have the pull rope start option?

I see they have a 24v slave cable plug on them. I think it is for starting the generator from a truck, but what about the opposite? If you pulled started the generator, could you then use it to jump start a truck?

Derek Taylor

 

[chadande]

The Yanmar repowered units have the pull start, the Onan powered units do not.

The slave plug is to start the generator, but I doubt the little 24V battery in there would be much use in jump starting a truck.

 

[Triple Jim]

On the other hand, it might charge a truck's battery in a few minutes (1/2 hour or so?) enough to get it to start.

 

[Isaac-1]

Be aware that people have reported overheating problems Yanmar repowered MEP-701a's as the Yanmar engines don't have duct work to line up with the cooling ducts in the 701a ASK like the Onan powered MEP-016B's did.

Ike

 

[derf]

That is one reason I ditched the ASK from the 016E/701A that I got.
If you get a 701A with a Yanmar just remove the ASK kit and you have a 016E. You could probably leave the top on.

 

[helomedic1171]

As for jump starting, yes, it will work, but you have to let the genset charge up the batteries a bit first if they're REALLY dead. if you just left the lights on too long, it will likely allow you to crank the truck if it otherwise would normally crank. Meaning, don't take it to instantly start your next GL auction purchase thinking you'll be good to go in 10 minutes. I'm talking about the 10k and larger units. the smaller ones wil also help, but would be better for charging the batteres, not actually cranking the truck.

YRMV, the above is only my experience starting Mil trucks with various combinations of whatever slave outlet I had readily available and producing power. sometimes, it just takes too much time to move another vehicle if you have a perfectly good genset parked right next to your dead truck.

 

[flibob]

I like my 701 but it is electric start. It also weighs over 500 lbs. You really need a forklift or tractor to move it.

 

[Isaac-1]

I have to disagree about needing a forklift of tractor to move the MEP701a, sure you can't just pick the thing up by hand unless you have a few strong men, but I was able to unload mine off a 5x8 utility trailer and get it into place on some concrete pavers next to my shed all by myself. (well with the help of some scrap iron pipe for Egyptian style rollers and a $20 cable hoist with a tow strap fastened around a nearby oak tree to drag it into place in about 15 minutes). Getting it down to ground level from a truck bed would have been a bit more of a challenge, but certainly possible, we are only talking a little over 500 pounds). Now a MEP-002a at just under 1,000 pounds would be another story, for mine I did use a tractor with a front end loader.

Ike

 

[helomedic1171]

i had my 003 loaded into a 5x7 enclosed trailer at the RAFB GL site. when i got home, I looped a strap around a tree and hooked it to the sling loops/rings on the genset skid, and slowly drove forward. the genset slid off very gently and stayed put while I parked my truck. then I used my engine hoist to pick it up and then moved it where i wanted it.

 

[TaylorTradingCo]

help

Thanks for the info. guys. I am glad I asked before I bid. I definitely want the ability to hand crank, so it looks like the 701 is out of the question, but now I know better what to look for.

Looking at the MEP-016's, I see several different suffixes, such as B, C, D or E. Are there any real differences or any preferences?

Is the Yanmar a multifuel type motor?

Is it a good motor of not encased in the 701 ASK housing?

Derek

 

[Isaac-1]

I have posted a longer version of this before but here goes the short one:


MEP-016a / MEP-016c oldest 016 series Gasoline powered units, not fuel economic, rope pull start only, Vietnam era (I think the c is the same as the a, but with electronic ignition, I do know there was a retrofit option to add electronic ignition to the a series, and I think that would turn them into c series)

MEP-016b - same generator end as the a/c version, everything else different (frame, gauges, cabinet, electronics, etc.) 1 cylinder diesel built by Onan mostly in the 1980's, this engine almost exclusively used in this model, MEP-701a is a MEP-016b with ASK housing, also sometimes seen in another trailer mounted weather housing that looks similar to the 701a housing

MEP-016d -life extension retrofit (started around 1998 ) of the gasoline a or c models using a Yanmar L70 diesel, has pull start as well as electric starter connected to a slave port, but no on board battery and no battery charging system

MEP-016e - life extension retrofit of the MEP-016b replacing the Onan diesel with a Yanmar L100, has onboard battery, starter, charging system, mode advanced control box, etc.

p.s. note from a engine displacement point of view the Onan is still much larger than than either of the Yanmar's and does therefore consume a little more fuel, but seem like a much more robust design (external oil cooler, real spin on oil filter, not just a little cleanable oil strainer, etc . (also MUCH LARGER air and fuel filters)

Also if looking at GL, note the Yanmar retrofits may be listed by their original A,B,C designations and even show gasoline for the fuel, instead of the D or E variants, and often the retrofit model number plates were never installed or the original plates were not removed / scrated out, so look closely at the photos. Quality of the work on the retrofitting is variable, sometimes done in the field, other times by contractors, even exact parts used may vary (type of hose, fuel pump, even if the metal belly tank on the a/c versions was used at all or replaced with a plastic tank).



Ike

 

[derf]

I like the 016D the best. The E variants have a 10HP Yanmar which I feel is wasted on a 3kW gen.
The Yanmars will run on veg oil and other things, but I don't think they are mufti-fuel in the same way the Dueces are.

 

[W8BUH]

I have a MEP 701A and the fuel solenoid will not pull off any ideas out there what might be the problem? It is not the solenoid. I checked them. All ok.

 

[derf]

Have a look at the schematic and see what else might keep the solenoid from doing what you want it to do.
Probably the low fuel shutdown circuit. Stick your arm in the tank and hold the float up. If it runs then look into the low fuel shutoff.
Surging and such caused by running out of fuel, not to mention having to re-prime a Diesel fuel system, is why they chose to have a float to shut down the unit when the fuel dropped below a certain level.
Or, not. Just my opinion. More info would be appreciated. Let everyone know when you figure it out.

 

[ETN550]

It seems like we just had a post regarding the fuel solenoid not working. See if you can find it. Unplug the solenoid and make a jumper using standard crimp on female spade connectors. Short the solenoid to the battery and see if it works. Usually it does and the problem is elsewhere. See above about doing the float test. In a properly functioning system the main switch can be in the run position and moving the lower float up and down will cause the solenoid to clack loudly on and off and on, etc. If the float test does not move the solenoid then listen very carefully using a screwdriver on your ear and on the proper relay on the board to see if the relay is working as the float goes up and down. If the relay on the board clicks then the master switch, float, and relay are working. Working backward from the solenoid the power comes from a relay on the left side board in the control box and the relay coil runs through the float switch and gets its power from the main "run" switch. Usually, the connector at the solenoid may be loose or bad, the float may be bad, or the wiring or a ground has an issue. The relay and the master switch are rarely bad. Also, the relays can be flipped over and a fresh set of contacts will be used. So flipping the relay is another thing to try. The plug connector on the solenoid can be carefully taken apart and the female spade ends can be closed tighter with pliers to make the connector grip the male spades on the solenoid better. The wiring diagram under the lid shows all the components and the wire and plug call outs from the solenoid all the way back. It takes some time to read all the index of components and figure out the diagram so use a pencila nd paper to make notes, its easier. Its just a matter of tracing it backwards from the solenoid. If the float is bad it can be bypassed by jumping wires in the box to make the relay stay on with the master switch but remember what is said above about running it out of fuel.

 

[W8BUH]

ENT 550 Question for you.
Right above the govern is a shaft.The shaft comes out right below the linkage that has the yellow on it. Can you tell me what that does? It goes into the block of the engine and is froze up. On the other one I have it moves freely.
Thanks

 

[ETN550]

If it is the shaft that has the round button on it's lever that the the fuel solenoid is pushing against then that means the injection pump plunger is frozen in the injection pump. The injection pump bolts in from the top and it has a pin that is moved by a fork inside the block on the end of that shaft. The movement rotates the barrel in the pump which is how it makes more or less fuel.

Funny thing is I have never had an issue with one of these and when I went out in the shop tonight to look at a unit I have but not started work on I found the exact same problem, a frozen injector pump that will not allow the shaft and lever to move! Weird, huh?

Safest thing to do is to pull the injection pump and try to get it loostened up. Cranking the engine over could damage it or it could loosten it up. Most likely if it is sticking then the cam will force it up and it will stay stuck up as only a spring returns it.

Pull the injection pump, make sure to save and reuse any shims between the pump and the block as that is how the pump is timed. I've not had one apart yet but the job will be to soak it and try working it loose and disassemble what can be taken apart realizing that absolute cleanliness is needed to reassemble it. Sometimes they are reassembled under fuel. If it can be taken apart to where the stuck plunger and barrel can be exposed then heating the barrel carefully may expand it enough to work it loose. A small propane torch with a low flame would be ok.

The injection plunger and barrel may have a clearance of only 10 - 50 millionths of an inch so it is not uncommon for them to stick even from sitting even if there is no water to cause corrosion. There is probably a good chance it can be freed up. I'll let you know how mine turns out and what I do to it. Mine has all the lines on it so I doubt there is water in it.

 

[W8BUH]

ENT550 You call it the injection pump is it the same as the fuel pump or the metering pump?
I have a picture is it the one on the right or left. Sorry to act confused but it is the first time dealing with a diesel engine this small.
Thanks again for all the help.. Dean

 

[ETN550]

Metering pump. The one on the right. After removing all the lines it should lift straight out when unbolted from the block. The steel line on top goes to the injector. Try loosening it on the injector as well and see if it can be moved out of the way. If it has a clamp on it somewhere then the clamp will have to be removed to allow the line to be taken off. Try not to bend it. The steel line is pretty stiff. If bent it will be harder to get it back on and seal tight later.

I'll be working on mine in a few days.

 

[jonster]

About the stuck cut-off solenoid. I have had three 701a's and two of them had bent solenoid brackets. The end of the solenoid was getting hung up on the engine. When that happens you end up melting a diode on your engine control board. I placed a few shims in and the solenoids worked just fine.

Good Luck!