4A084 engine info?

[liftman]

It's on a tapered shaft with a key. I don't remember having to use a puller, but if i did, it was only a small steering wheel type. I think I just jarred it loose with a rubber hammer. As far as getting the nut off, an impact won't have a problem.

Tightening it, according to the TM requires 80-83 ft lbs. That's not a problem with a strap wrench holding the pulley while using the torque wrench. I guess you could take it off the same way if no impact is available.

 

[callbt]

Hello,
Ok some pics of what used to be the 4A084's governor. As you can see it appears one of the "follower buttons" came out due the cracked holder. The button then wedged it's self at the base of the weight pivot and gouged out a new groove in the aluminum housing. NOS governor on order from E-bay for $38, so I should be able to get the beast running again once I take the cover off and look for the missing half of the roll pin that sheared off.
any one know how fine of mesh the oil pick up screen is?

 

[littlebob]

Trying to get the engine running in my M51 Shelter trailer.
Cranks fine, but no spark.

Questions:
1. There is a single white wire going to the magneto. Is that wire supposed to be hot when the engine switch is on, as in a distributor system? Or does that wire go to ground when the engine switch is off, killing the engine?

2. Wiring diagram shows wires A thru J coming from AC alternator. The "alternator" behind the rope-start pulley only has 2 wires coming from it. Is diagram referring to the 3-phase generator driven by the engine?

I realize there could be a points/condenser problem, but I'm looking for simpler fixes.

I just want to see if it will run, then I'll start checking out the other components.

Appreciate any help.

Mine was the points. I don't remember having to remove much to get the magneto out though. I'll try to find some pic's and stuff and PM you. I remember
asking for help when I was having a problem. If I can find the thread, I'll copy it here.

 

[littlebob]

Lost the Internet for a day and realized this was an old question. If anyone needs the TM's and the they are
inaccessible here, I can get them to you

 

[liftman]

Did you check to be sure the governor is getting oil from the line? It seems that a failure like that may be caused by poor lubrication to the governor.

 

[cbvet]

I will be working on mine again when the weather warms up. Assuming that it will, of course.
I appreciate all the useful info this thread has generated.

 

[callbt]

Hello,
Yes I've got oil squirting from the line- checked this my mistake one time while setting the timing (turning engine over) without the oil line attached to the governor- plenty of flow!

Ok I already got my new governor off E-bay, but curious if I could of used a 4A032 governor instead- yes it's assembled upside down, but that's easy to reconfigure and save $15. The casting looks identical from the pics I can find, just mounted upside down on the 4A032 engine.

Brian

 

[callbt]

I finally got around to removing the pully and gear train cover- found plenty of AL shavings and the broken spring/roll pin. Now the question is how do I know when I'm at top dead center for Cylinder #1 ? Is this the timing mark on the gear that I line up with for the magnito? which I need to verify as well since the gear is off, so I've got a 50/50 chance of getting it right, but will remove the mag cover (again) to verify. sincerly Brian

 

[liftman]

The timing mark on the lower (crankshaft) pulley will show you TDC. Pull the #1 valve cover off to be sure you are not on TDC on the exhaust stroke.

At that point, a timing mark on the cam gear shows you where the magneto needs to be placed. You have to wind up the impulse coupling on the magneto before engaging the timing mark, or the ignition timing will be very late. You can check to see if it is right after installation by turning the magneto slowly. You should here the impulse trip which will set the timing at 0 degrees, as long as you haven't turned the engine.

The above is much easier to do with the governor out, as you can then see all of the marks.

 

[callbt]

Hello,
Yes I'm still repairing the mess from the governor crash... I've got the pieces cleaned and gear cover back on along with the rope pulley/dampener. Following liftman's advice, I proved that I'm at TDC by taking the valve cover off cylinder #1. This proved my theory that the mark on the cam gear will ony be viewable in the governor opening when it's at TDC for cylinder #1

I'm about to reassemble the magneto... and I'm trying to make sure I've got the gear back on correctly.. it appears to have two position possible- why do I need to "wind" the impulse coupling? Is this just to see that I'm timed to 0 deg?

Once I get this re-assembled, I've got a timing light to set the magneto and hopefully be fully functional again.. just need some gas cans- thinking of using a portable 12 gal marine fuel tank for easy hookup. I've removed all the old Jerry can setup and added an in-line filter like I used to have on my old VW Bug.

Thanks for all the help thus far,
Brian

 

[liftman]

The spring on the mag has to be wound before engaging the cam gear because the marks have to be lined up when the spring is under tension. If it is not done that way, the spark when cranking slow will be too late for the engine to start easily. The spring allows the magneto to "snap" when it reaches TDC for each cylinder when cranking slow. After the engine starts, the spring is no longer needed simply because the engine is turning fast enough to generate a strong spark from the magneto.

 

[callbt]

Hello,
OK, but as long as the marks are lined up (spring under tension or not) the mechanics within the magneto will re-tension the spring as I crank right? If not what re-sets the spring after it's "tripped"?


Brian

 

[liftman]

When the engine is turning slow, as in cranking to start, spark has to occur later in the stroke than when it is running. This is done with the impulse coupling on the magneto. The coupling has a set of dogs that protrude from the housing and contact a stop pin when the engine is cranking to start. The dogs and the stop pin allow the spring to wind up, preventing the points from opening until later in the cycle, which retards the timing and allows for easier starting of the engine.

Once the engine starts and is running, spark needs to occur earlier because of rotating inertia. The dogs on the impulse coupling are attached to a set of flyweights that pull them into the impulse housing once the engine is running. This allows the points to open earlier and effectively advance the ignition timing.

 

[callbt]

Hello,
Ok a few nights of thinking this all thru and the engine is up and running again. The whole needing to wind the system prior to install appears false ( or I just got lucky). Basically I had to insure that #1 cylinder was at TC of the compression stroke- ready to fire. The other trick is to take the cover off the Magneto to see where #1 wire goes and aligns with the internal distributer- which is on a 2:1 gearing- meaning there are two revalutions to the gear on the magneto with timing mark. My magneto gear came off too, so that has two more possible positions. Just make sure #1 location is set with timing mark in place and it works fine. Now I got questions about how much power I can get of out 240 single phase? It seems that I'm only going to get 7,200 watts (240v x30 amp for each leg). Any way to full 10Kw in single phase?

Brian

 

[liftman]

Description of the generator capacity copied from the TM is below. I wouldn't trust the gauge on the set. Check it with an Amprobe to be sure. If it doesn't produce capacity, usually the issues are with a poorly running engine or governor problem.

The Model MEP-018A generator is 60
hertz. The voltage rating is120/240 and 120, 1 phase
and 120/20 8 and 120, 3 phase to voltage ratings. The
amperage is 3 phase connection load current, 34.7
amperes per line, 1 phase connection load current, 104
amperes and 52 amperes load current on 240 volt​

connection.

 

[callbt]

Hello,
The engine is running great thanks to the previous help. putting out ~118 volts per leg and governor set so I get 60hz based on my kill-a-watt meter. When I attempt to start my house Air conditioner, I trip the circuit breaker on the Genset, 30 amps per leg. The breaker on the house panel is 40 amps 240 volt.. I've checked voltage at the outside disconnect, still 118volts, everything else off in the house. Even tried with fan running first so the start up load didn't overload one leg since it's just a 110 volt fan.

Sincerely,
Brian

 

[liftman]

Could still be a governor problem. Does the engine "droop" excessively when the load is applied? That can cause the breaker to trip.

You might want to try using resistive loads to test the capacity, like would be in a load bank. That way you could tell if the set is developing it's full capacity.

 

[jbk]

my 018 did somthing similar. wouldnt take more than 4500 watts and couldnt get more than 116 volts ac at 60 htz.. would throw the breaker when i tryed the central ac. . turned out to be a weak a/c voltage regulator. i had an old style. put a new v/r on it and it takes the full 10 kw.

 

[callbt]

Hello,
We lost power last night and the MEP-018a fired right up, though the engine kept surging- as if the governor was trying to over compensate. I let the engine get warmed up for ~5 min and the surging wasn't as bad. Though I'm thinking my adjustments on the governor are not correct. I ran for ~2 hrs before I shut the unit down. I'm partially thinking that the engine is "miss firing" every so often since it's not a steady rpm. I thought about disconnecting the governor and just set the throttle manually to see if the engine would run steady without powering anything.

Anyone have a simple way to set the two adjustments on the governor?

As for a weak voltage regulator- how would I prove that? I can adjust power up and down without any issue.
Any thoughts on how to load the generator up to test the current draw on each leg with a amp meter clamp short of two ovens and an electric water heater?


Sincerely,
Brian

 

[liftman]

Surging usually means the governor is not controlling the speed properly or there is a fuel problem. Have you cleaned the carb thoroughly and using fresh gasoline? Ethanol gasoline tends to break down quickly. Are all of the linkages to the governor and carb free from sticking? This could cause the governor to over compensate and cause the surging.

The best way to check AC output is with a resistive load, as in two ovens and an electric water heater. The TM gives the best procedure for governor adjustment. Just be sure that you are at 60hz at governed speed, which should be approx. 3600 RPM.