Who has an MEP-016E?

[ETN550]

If you get 24V at the pump and the pump isn't moving fuel then the pump is bad. You may be able to switch the main and aux pumps and get it to work. If no 24V at the pump then maybe something else is wrong.

If it ran for a while and then stopped you may have to bleed the fuel system once you get the electric pump working.
IIRC there is a nice little Facet pump that costs less and works well. ebay and Aircraft Spruce are sometimes good places to find 24V DC fuel pumps.

Agree. If the pump does not work with 24vdc applied first take the end cap off and make sure the plunger can move freely. If it does move freely reassemble and cut out the RF supressor and wire it direct and try again. 50% of the main pumps I see on the 016E are bad and 50% of those bad ones will run with the RF supressor cut out of the wiring.

Not that we can do anything about this but it seems as though the newer round pumps like those supplied in the conversions operate slightly differently then the old round style. I have noticed the old style only move back and forth when fuel flows. This action can be heard on the countless videos of people priming and running the engines. they click rapidly until fuel pressure builds then they click slowly. The newer style tends to oscilate rapidly but with tiny strokes whether fuel is moved or not. And another possible issue is the Yanmar fuel system is dead headed. That is there is no return line from the injection pump to allow constant fuel circulation. I think the pumps live best when they can circulate some fuel to stay cool and allow the plunger to stroke more like on the MEP 002 and 003 systems. I have been tempted to make a bypass line with an orfice from the line to the injection pump to the return line to the tank. The injection pump itself only needs gravity feed.

If anyone experiences multiple pump failures on the 016E I recommend they try making the bypass line. I'm pretty confident the pumps would live longer if they constantly circulated fuel. I would prefer finding a running used old take out pump over new one at this point. Fortunately, the aux pump is usually old and can swap in place of the main pump that has failed. Then put the new replacement in the aux position where it might live.

 

[Grove]

The pump was stuck and the RF box was also bad. The problem is that I'm still not getting power to the pump. With a jumper wire from the battery to the pump the unit runs great. Since the actuator kicks on with the switch moved to run am I correct in assuming my lower tank float switch is working? I know the upper one is good.

Thanks,
Grove

 

[ETN550]

The pump was stuck and the RF box was also bad. The problem is that I'm still not getting power to the pump. With a jumper wire from the battery to the pump the unit runs great. Since the actuator kicks on with the switch moved to run am I correct in assuming my lower tank float switch is working? I know the upper one is good.

Thanks,
Grove

Yes lower tank float is working if the fuel pump solenoid kicks on. But, just to make sure the float has not been bypassed put the switch in the run position and move the float up and down and confirm the solenoid going on and off as the float is moved. Put a meter on the wire to the pump and confirm it is not getting 24vdc with switch on. The wire will have to be traced back to the control box. I forget how the 106E fuel pump is wired but the the same relay on the board that operates the fuel solenoid also activates the primary fuel pump. If you find the output to the fuel solenoid on the board then the fuel pump wire should also be taken off the same terminal. As a quick fix the fuel pump hot wire can be connected to the hot input wire on the long cigar shaped fuel solenoid timer under the fuel filter. The input on the cigar is the side with 2 wires. The output on the cigar has 3 wires going to the fuel solenoid. By connecting to the hot input the pump on and off will be timed with the fuel solenoid. Since the same relay and circuit serve both fuel solenoid and fuel pump anyway there is no concern for overloading a circuit.

 

[pahunter]

The stuff below the fuel filter is as follows:

2 small identical relays side by side are for the grid heaters. All incoming and outgoinjg wires are split so each relay coil and relay contact sees half the load. Strange.

The large cylindrical unit with the hoses is the primary fuel pump that takes fuel from the tank and pushes it through the filter to the injection pump.

The square block in the wiring for the fuel pump is an RF suppressor.

The long cylindrical piece has something to do with the fuel control solenoid. Two wires come in but three go to the solenoid.

The speed or frequency is no longer adjustable from the panel. The adjustment is made by screwing the solenoid plunger in and out making it shorter or longer. There is a small locknut to loosten and the long barrel nut can be held while the flats on the backside of the plunger can be turned. I just had one in that needed adjusting and although it looks kind of hokey one full turn is less than one Hz so it is pretty easy to get set accurately with a few tries.

A note on cooling these engines in the 701A housing. I believe converting the enclosed 701A to Yanmar was a mistake. The Onan discharged its cooling air out the top and was designed to do so from the start. The Yanmar does not so the hot air off the head and cylinder gets trapped in the housing and recirculated causing overheating. Witness the huge number of 016Es that have a frame with the inserts to take the 701A enclosure but have no enclosure. I believe that the military eventually stripped off the enclosure when adding the Yanmar. I have studied some enclosed units with Yanmar. My latest is a pump. Runs very quiet and has a sheild inside so the fan intake around the recoil starter cannot pull hot air. So I conclude that to properly use the Yanmar in the 701A enclosure there needs to be modifications so the engine and generator fan intakes are only sucking cool air. Then I think it would work. Might try this mod myself if I ever have enough time.

Also, if anyone is interested I just completed my 4th generation battery tray to convert the single 24 volt 4HN battery to Two 12 volt lawn and garden tractor batteries. This latest version will fit the two batteries inside the existing 701A enclosure with a small modification. I can post up some pics if interested. Several advantages to Two 12volt batteries. (Under $30 each, more total amps possible, Jumper wire disconnect allows charging with 12volt charger, batteries very available at any auto store or walmart. I bought 11 batteries for $21.95 ea at Advance Auto. they had a sale in March - April. I'm thinking of offering conversions if interested. I have converted 11 total so far. 016B, 016E and 701A.

You still making battery trays?

 

[pahunter]

You still making battery trays?

Made one, not as nice as the one I saw on here but it’s sturdy.