# Coleman Powermate Low Voltage



## Fisher77 (Aug 3, 2021)

New here and hoping to get some help. I have a Coleman Powermate PM0525302.03 with a Tecumseh HM100-159402T.
When I first got it it was putting out 140v, but I noticed the Tecumseh was wrapped up pretty high, 8600 rpm's to be exact.
I adjusted the govoner and got it down to about 4200 rpm's, still a little high but better than it was. For some reason it does
not run good at 3600 rpm's. But I will tackle that later. At the moment it is only putting out 74v. I changed the cap already, and
cleaned the brush commutators. Brushes are about 5/8" long. Tested the diodes with my multimeter (on diode check) and they
were good. Both tested at .5 volts. I also tried flashing it, with no change. I added another cap across the brushes on the outside 
and it jumped to 80 volts. Thats where I am at the moment. 

Does anybody have any idea's on what might could be causing the low voltage?


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## tabora (Sep 6, 2018)

Fisher77 said:


> Does anybody have any idea's on what might could be causing the low voltage?


If you ran it at much beyond 3600RPM, you killed the regulation capacitor. It's #10C in the diagram and parts list. First, get the engine running at 3600RPM (that's how you get 60Hz and 120V). Order a replacement capacitor on eBay with the same specs (read them right off the existing cap) and you should be all set. If you need help matching it, provide the exact imprint info or a picture.

It may be this one: https://www.ebay.com/itm/273595915553?epid=131088453&hash=item3fb3965d21:g:MNgAAOSw5wFcB9~f


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## iowagold (Jan 22, 2020)

adjust the rpm by hz.
what is the hz on the set up?
it needs to be at 1/2 rated load 60 hz
use a space heater or two for the load


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## Fisher77 (Aug 3, 2021)

tabora: The cap in it is 130 microfarads, 200 volts. According to the parts websites it is nla. The cap you found on
ebay should work. I appreciate it. I will order it.

iowagold: The hz on the tag says 60. I measured the hz with no load and it was at 35hz @ 70 volts. I plugged in 2 space heaters and measured 30hz @ 50v, 3600rpm.
The hz was measured with my klein tools dmm, rpm is being measured with my MAC dmm with inductive pickup.

Greatly appreciate both of you for replying.


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## tabora (Sep 6, 2018)

Fisher77 said:


> The cap in it is 130 microfarads, 200 volts.


I usually try to match them exactly, but that seller states: *Capacitor has been changed from the original 130uF to 220uF to help increase the life of the capacitor.*
If it doesn't work, return it under the "Not As Described" criteria, since he lists your specific model number.


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## Fisher77 (Aug 3, 2021)

Thanks tabora. I might could find the exact value on mouser, digikey, or newark. 
I also was wondering: Should the engine run 3600 rpm's constantly, or should it idle down?


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## tabora (Sep 6, 2018)

Fisher77 said:


> Should the engine run 3600 rpm's constantly, or should it idle down?


The manual doesn't show any idle-down switch; in order to produce 120/240V @ 60Hz, the genset must be turning at 3600RPM.


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## Fisher77 (Aug 3, 2021)

I installed the new cap. Start it up and still only puts out 30 hz @ 50 V at 3600 rpm. I don't understand it. You can accelerate the engine to 6000 rpm and get a 120 V out of it.


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## McCorby (Apr 26, 2021)

8600 rpm!!! If that Tecumseh was actually able to reach those rpms without floating the valves and grenading, then it’s likely running on borrowed time (damage is probably already done). With that said, if you continue to run it at speeds north of 4500 rpm, it’s not if, but when the connecting rod will make its exit through the side of the crankcase in a very spectacular fashion! The engine wasn’t designed to run much over 3600 rpm. Sure, you can run it a little faster, but I wouldn’t recommend running it over 4000 rpm for extended lengths of time. Ymmv!


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## iowagold (Jan 22, 2020)

check the tach
my small engine tach has several settings for 1,2,3,4 cyl engines.
as well as 2 cycle and 4 cycle settings.
it could be set wrong.


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## McCorby (Apr 26, 2021)

Fisher77 said:


> I installed the new cap. Start it up and still only puts out 30 hz @ 50 V at 3600 rpm. I don't understand it. You can accelerate the engine to 6000 rpm and get a 120 V out of it.


30 Hz at 3600 rpm is not possible. 30 Hz equals 1800 rpm with a two pole rotor. What are you using to measure rpm and frequency?


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## Fisher77 (Aug 3, 2021)

Hz with a klein tools dmm set to hz, rpm with a mac tools dmm set to rpm and 4 stroke, using a inductive pickup on the plug wire.


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## LaSwamp (Mar 16, 2021)

How old is the generator? Tecumseh is a name I've not heard in quite a while.


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## McCorby (Apr 26, 2021)

Fisher77 said:


> Hz with a klein tools dmm set to hz, rpm with a mac tools dmm set to rpm and 4 stroke, using a inductive pickup on the plug wire.


I’m guessing your rpm measurement is incorrect. After more thought, there is no way that Tecumseh is able to run at 8600 rpm. You are likely reading double the actual rpm. Like Iowa suggested, your rpm meter is likely setup incorrectly or it’s faulty. Your frequency measurement is much more believable.


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## McCorby (Apr 26, 2021)

LaSwamp said:


> How old is the generator? Tecumseh is a name I've not heard in quite a while.


Tecumseh went out of business in 2009.


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## Fisher77 (Aug 3, 2021)

McCorby said:


> Tecumseh went out of business in 2009.


I believe it is a 2006.



McCorby said:


> I’m guessing your rpm measurement is incorrect. After more thought, there is no way that Tecumseh is able to run at 8600 rpm. You are likely reading double the actual rpm. Like Iowa suggested, your rpm meter is likely setup incorrectly or it’s faulty. Your frequency measurement is much more believable.


I will double check it tomorrow. I can hook it to my lawn mower and see what it reads. It only has 2 settings. Dial set to RPM, range selects either 2 or 4 stroke.


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## iowagold (Jan 22, 2020)

i do not think that will work for the gen


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## Fisher77 (Aug 3, 2021)

iowagold said:


> i do not think that will work for the gen


What would you recommend?

Found your PM. Thanks for the links!!


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## McCorby (Apr 26, 2021)

On a non inverter generator, output frequency works just fine. 1Hz = 60 rpm with a 2 pole rotor (60Hz = 3600 rpm). 1Hz = 30 rpm with a 4 pole rotor (60Hz = 1800 rpm). You have a 2 pole rotor.


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## Fisher77 (Aug 3, 2021)

iowagold said:


> check the tach
> my small engine tach has several settings for 1,2,3,4 cyl engines.
> as well as 2 cycle and 4 cycle settings.
> it could be set wrong.





McCorby said:


> I’m guessing your rpm measurement is incorrect. After more thought, there is no way that Tecumseh is able to run at 8600 rpm. You are likely reading double the actual rpm. Like Iowa suggested, your rpm meter is likely setup incorrectly or it’s faulty. Your frequency measurement is much more believable.


Ok I just tested the MAC DMM on my lawn mower. You guys are absolutely correct. The meter is reading 6200 rpm on the mower. I also tested on my tiller with a 5 hp Tecumseh and it read
9800 rpm. So at this point I am going to adjust it to 60 hz output as suggested above by iowagold and McCorby. I am also going to order the rpm meter that iowagold suggested from the tool pages.
I appreciate all the help you all have given me sor far.


(Update): I adjusted to 60 hz output @ 120 volts with 2 space heaters connected. For grins and giggles I hooked the MAC DMM back to it to check the rpm. The rpm's read 7200 and some change. Of course divided by 2 that is 3600 rpm. I will post back on the exact rpm when the new meter arrives, although I am sure it will be right around 3600.


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## McCorby (Apr 26, 2021)

Glad you got it worked out! I personally would trust the generator frequency accuracy more than a properly setup/functioning inductive tach….

4900 rpm (9800 rpm on your meter) is way too fast for your tiller motor btw. Check the specs, but I’m pretty sure it should be running at less than 3600 rpm. I’m guessing somewhere between 3200 and 3400 rpm.


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## iowagold (Jan 22, 2020)

Ha!
cool glad you are up and running!
yea set the basic gens on fq you should be spot on at that point if the mechanical speed gov is working right.


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## Fisher77 (Aug 3, 2021)

McCorby said:


> Glad you got it worked out! I personally would trust the generator frequency accuracy more than a properly setup/functioning inductive tach….
> 
> 4900 rpm (9800 rpm on your meter) is way too fast for your tiller motor btw. Check the specs, but I’m pretty sure it should be running at less than 3600 rpm. I’m guessing somewhere between 3200 and 3400 rpm.


I will adjust the tiller when the tach gets here. Soon as I started it I knew it was running to fast(sounded like a runaway 71 series 2 stroke Detroit Diesel).




iowagold said:


> Ha!
> cool glad you are up and running!
> yea set the basic gens on fq you should be spot on at that point if the mechanical speed gov is working right.


Gov is working good. I plugged a 1100 watt window unit into it. When the compressor kicked in it lugged the gen down. Gen sped back up to make up for the load.


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## WandaRobertson (Aug 8, 2021)

Welcome aboard.


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## Fisher77 (Aug 3, 2021)

New RPM/Hour meter came in today. Got it installed. Gen is doing 120 volts, 60 hz, 3600 rpms. She is good to go. I really appreciate everyones help with this. 

Now if you guys can tell me how to install silent mode on this unit, I will be forever grateful.....LMAO


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## iowagold (Jan 22, 2020)

there is a factory installed switch for that......
OFF
lol!
sorry i had to go there!

well there are mufflers that are better than the oem.
and now they even make cat converters for small engines as well.

they have those gen stacks to get the noise up in the air.
but a lot of the noise is also from the thin block...

this is one of the reasons i love the eu7000is honda gen..
they are pretty quiet...

and there is nothing more annoying than a LOUD gen set near by if you do not have power and have the windows open in the heat to try to keep cool...
same in a camp ground....

they make zombie boxes that help a bit on the noise...

there are also water mufflers that works like a marine engine muffler..

let me know if you need links!
and yes these need a quiet box for sure!


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## Marlin (May 25, 2015)

The reason that your first testing was showing an RPM over 8,000 was because you had your tachometer set to "4 cycle" as you said in entry #12 above.

With an inductive pickup like you said you were using, you must choose the "2 cycle" setting.

You see, there is a spark at the plug at the top of the exhaust stroke.

If you think about it, you will realize there is no difference between the ignition system on a small 4 cycle engine and the ignition system on a 2 cycle engine.

There is no provision for eliminating the second spark every time the flywheel magnets go past the coil.


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## Fisher77 (Aug 3, 2021)

Marlin said:


> The reason that your first testing was showing an RPM over 8,000 was because you had your tachometer set to "4 cycle" as you said in entry #12 above.
> 
> With an inductive pickup like you said you were using, you must choose the "2 cycle" setting.
> 
> ...


Your absolutely right. Never even thought about that.


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