MEP-002A hz dropping under load

[toypar]

I have had this MEP-002A for a few years now. It has been in storage while I have been working on the road and has been started once a month or so. I finally bought a place here in East Texas and moved it down here from Oregon with me. We had a power outage last night for a few hours. I am able to start the unit and it seems to run just fine and 62 hz and puts out proper 240 voltage. When I put any load on the gen set past 25 percent, the HZ drops to around 58 hz and I have to go out and adjust it with the knob on the front.

Now today I wired in one heating element off an old water heater. One element is supposed to be 4500 watts at 240v. Generator was set to 62hz and when I turned the element on it dropped to 55 hz. Is this normal? or is it an excessive amount of droop? I also get zero black smoke when loaded down. When at 55 hz, I can manually go out and crank the knob to get proper 60 hz. The issue is when the load is removed it jumps to 65 and stays there.

My brother has a MEP-003a, and when we load it down with 12k watts it puffs black smoke for a split second and keeps on going like it isn't there. It just seems like the 002a maybe isn't able to get full throttle? Seems like at this moment it has very little surge capabilities. It has the ASK kit, and I haven't had a chance to pull the side off yet. Does this sound like a governor problem?

 

[Isaac-1]

Check the linkage on the expandable part of the governor arm and make sure it did not come unscrewed part way during the move

 

[toypar]

I am trying to find clear pictures of the linkage on the web. I won't have a chance to look at it for a couple days. Are you talking about the part with the spring and star adjuster?

 

[Isaac-1]

I am talking about the collapsible linkage connected to the injection pump that then connects to the linkage to goes to the spring and star wheel adjuster. Its length is set by turning it in or out then locking in place with a pair of locking nuts, if these nuts back off it can unscrew and lengthen which can result in the symptoms you describe. The TM tells you what the proper length is in the compressed position, but I don't recall it off hand. You do not have to remove the fan shroud to get to the part I am talking about.

 

[Jimc]

as isaac said, first thing is to check the linkage. some other things that could cause this is old fuel, injectors needing a tune up and low compression.

 

[cuad4u]

Also check the Hz "droop" adjustment on the spring and notched "wheel" on the governor linkage. This adjustment is located just inside the fan housing but can be adjusted without removing the fan housing. Squirt a little penetrating oil on the adjustment wheel first. Then using a screw driver and a hammer, the notched wheel can be turned which moves the mechanism up and down. There is a section in the TM that tells you how to adjust it. When working right no load to full load Hz will not deviate more than a couple of Hz.

 

[Keith_J]

If over adjusted, the frequency will hunt or oscillate instead of drooping ( falling freq on load). Adjust for minor hunting when major load( 80% or greater of rated) is disconnected. Typically hunting should subside within 30 seconds.

 

[Ray70]

An easy way to check if the drooping is caused by the governor spring adjustment or a problem with the engine ( such as weak injectors etc.) is to set the frequency at say 62 then apply a heavy load. If you can correct the droop by manually pushing on the injector pump linkage then the problem is the spring/star wheel governor adjustment. The spring is too high. If you cannot overcome the droop by pushing the linkage then you have an engine power problem and will need to take a look at the injectors, IP, compression and related stuff.

 

[Ray70]

If you look to the right of the injector pump under the fan shroud you will find the star wheel that Cuad4u is talking about. It is attached to a coarse looking thread with the end of a spring hooked around it. Turning the star wheel will raise or lower the spring, bringing it closer to or further from the pivot point. Excessive droop means you're too far away from the pivot ( too high) excessive "Hunting" means you're too close to the pivot( too low). The TM explains the adjustment procedure and has a picture of it, but it's pretty easy to figure out once you locate it.

 

[toypar]

Thanks for the replies. I will tear into know. I'm thinking it has to be a governor linkage issue due to the fact I can turn the knob to get it to the correct hz.

 

[Keith_J]

An easy way to check if the drooping is caused by the governor spring adjustment or a problem with the engine ( such as weak injectors etc.) is to set the frequency at say 62 then apply a heavy load. If you can correct the droop by manually pushing on the injector pump linkage then the problem is the spring/star wheel governor adjustment. The spring is too high. If you cannot overcome the droop by pushing the linkage then you have an engine power problem and will need to take a look at the injectors, IP, compression and related stuff.

Or if the manual throttle at the control panel cannot correct the droop, then the engine is weak.

 

[toypar]

So I looked at the linkage and found the droop spring bottomed out already. I set the unit to 62.5 hz under no load. I applied the 4500 Watt water heater element and it brought the unit to 65 percent on the load meter. (old water heater, not sure if the elements drawing rated power) hz drooped to 59.5. I added a 1200 want heat gun which brought the meter to 80 percent. After about a minute the generator started missing and loosing rpms. It dropped down to 48hz and wanted to die. I took the load off and it jumped back up to 62 hz. I took the fuel cap off while running, it has 3/4 of a tank. I wasn't able to here any fuel returning to the tank with the unit off and fuel pump on. I think my issue is the unit has mechanical issues or I'm putting a bigger load than I think on it. It smoked very little when loaded to 80 percent

 

[Keith_J]

Sounds about right for 4500 watt water heater element.  Power factor is unity for resistive loads, these are rated at 80% power factor so that is why a load that would be 90% is only 65%.<br><br>Your issue may be with dirt and varnish in the injection pump.  Follow the throttle linkage to the injection pump.  Where it enters the pump, spray it down with Berryman B12 carb cleaner.  When disconnected from the governor, this linkage should move freely with metallic sounding stops at either end.

 

[cuad4u]

toypar - It appears to me that you MAY have a fuel problem or possibly an engine problem. I have two 002A generators. When I got them they acted similar to what you described. Both generators now have rebuilt IP's and injectors worked on by Storeman. Both of my 002A generators will power 8000 watt water heater elements without any black smoke or bogging the engine. At 8000 watts I can tell the engine is working hard but RPM and hz hold steady as does oil pressure. Under no load hz is set at 62.5. Under an 8000 watt load hz drops to 58.5 and stays there. When I increased the load to 8500 watts at 90+ ambient temperature, the cylinder head over temperature switch shut the generator down after around 15 minutes at 8500 watts, but the engine did not bog down or emit black smoke. Both generators ran fine at 8000 watts for as long as I cared to run them. I load tested them up to 8000 watts because I wanted to see what a "healthy" 002A would do. Now I know.

 

[toypar]

Is there anyway to positively tell the IP is bad and the injectors needing rebuilt? Are the IP rebuild able at home, or is something that needs sent off? When my key is in the start to run position with the motor off, the clicking from the pump seems slow. I don't really have anything to compare it to, but it clicks about every 3/4s of a second. Also no return fuel is being hear going to the tank. I haven't checked while running. I unhooked the Linkage to the IP and found I had full travel up and down with a "metallic clunk at both positions. It moves very easily. Is there supposed to be some kind of resistance on the IP arm? Also when pulling the cap and strainer out of the tank, I found it didn't store to well and there is white deposits and slight rust on it. I have added a few gallons of fresh fuel about a month ago. The fuel smells like varnish to me. Could this old fuel cause this issue? I think I will start there, drain the tank and clean it out.

 

[Isaac-1]

I would certainly try fresh fuel and maybe some good diesel additive before going to the expense of rebuilding an injection pump, many people use marvel mystery oil, or ATF fluid mixed in to try to clean the gunk out of the fuel system. The problem may also be a sticking injector, this is not something you can test yourself without a pop off tester ( broke down and bought a used one last year, I thought it was time as I have several diesel engines), or swapping out a known good injector nozzle. I am having a similar problem with a MEP-003a (have not had time to work on it the last couple of months) and part of the problem was caused by sticking injector and governor linkage issue, I have went from it pulling about 50% of rated load to about 85%, also changing out the bad injector nozzle made it start much easier in cold weather.

 

[toypar]

It has about 40 hours on the fuel filters. I think I will drain the tank, replace filters and see what it does. Are these filters available from napa?

 

[Isaac-1]

I get mine from Amazon

 

[toypar]

Thanks, filters will be here Sat. I will update then

 

[rosco]

Sometimes, cross referenced filters, don't have the proper gaskets with them. There is plenty written about this.