# Coleman Powermate of a Certain Age



## LaSwamp (Mar 16, 2021)

Hi guys. A friend of mine told me he has a older Powermate generator that is leaking fuel from the carb. I told him to bring it by the workshop and I'd take a look at it. When I saw it, the first thing I thought is that this thing is old. It looks older than the Powermate I have. And that thing is old. 




























I pulled the carb off and gave it a good cleaning. It was an aftermarket replacement that is still new. I didn't see any issue with it and it didn't look like it was leaking. I did replace one of the hoses that looked brittle, hoping that might be where the leak was. 

One thing I did notice that was very curious. It looks like this generator has a mechanical fuel pump. The fuel line connection on the carb is pointed down. The fuel line from the gas tank runs to a small box bolted to the engine. A second hose runs from the box to the carb. I've never seen a fuel pump on such a small generator. Everything I have worked with has been gravity fed. I tried to start the engine after I reinstalled the carb. I could not get it to start. And it began leaking fuel. It was not leaking from the carb. I think it was leaking from the fuel pump. 

Something else. It has two 240 VAC outlets, but they are like none I have ever seen. They have two top slots over a single round hole, but the slots are horizontal, not vertical. Perhaps that might help in determining how old the generator is. 

I'm not sure I could find parts, especially a fuel pump, on something this old. Anyone have any ideas?


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## Matt88-8 (Dec 27, 2018)

Got a picture of said fuel pump? Most of them are simple vacuum pumps. Cost about $25 on Amazon 

Sent from my SM-G973W using Tapatalk


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## iowagold (Jan 22, 2020)

snap a better view pix of the outlets.
it looks like a split 20 amp wall outlet
with 20 amps on each one.

they used to have those at the box stores back in the day.
late 1970's early mid 1980's


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## LaSwamp (Mar 16, 2021)

This appears to be what the fuel pump looks like. 

My preliminary research shows that this generator is from the mid-1980s. I had no idea it was that old. I'm sure the fuel pump is original to the generator. 

Is it possible that this pump is the source of the leaking fuel? I was not able to identify the exact location of the leak. When I was trying to start the generator, it was acting like it could not get fuel. I don't know why B&S didn't just use gravity feed. Using a fuel pump in a generator seems like excessive engineering.


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## drmerdp (Apr 10, 2018)

That’s even older then the one I had. Mine was a 5000watt with a 10hp Briggs but the fuel was a simple gravity feed.

Where is the pump? Under the carb filter cover?

Those outlets are probably just 20amp 240v receptacles. Common to old timey generators for heavy power tools back in the day.


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## LaSwamp (Mar 16, 2021)

The pump is next to the carb, mounted on the engine. It seems pretty exotic for a generator of that vintage. In modern times, it seems only the Hondas and the much larger generators use a fuel delivery system that fancy-pants.


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## Ground Fault (Jun 9, 2020)

Looks like a basic diaphragm fuel pump. It would seem that most any diaphragm pump _of similar size_ would suffice. When this is resolved you may want to consider servicing, or even better, replacing the needle bearings in the alternator. I have the same Powermate, although a few years younger. The needle bearings were toast.


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## LaSwamp (Mar 16, 2021)

Ground Fault said:


> Looks like a basic diaphragm fuel pump. It would seem that most any diaphragm pump of similar size would suffice. When this is resolved you may want to consider servicing, or even better, replacing the needle bearings in the alternator. I have the same Powermate, although a few years younger. The needle bearings were toast.


Can the fuel pump leak if it's bad? Like a bad water pump in a car? It's leaking fuel and it seems to be coming from the area around the pump.


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## Ground Fault (Jun 9, 2020)

It can leak, and in these types of fuel pumps it is surprising that they don't leak more often. They're just molded plastic around rubber or neoprene diaphragms, with no fasteners to impart sealing pressure. Add in vibration stress cracks on plastic: it's almost assured it's gonna' leak_ eventually_. Even with fasteners diaphragm pumps leak. Has on one of mine. More than once. I've got a double pumper diaphragm fuel pump: one pumps gas in to the carb, the second pump pumps gas out of the carb. The diaphragms acts as the gasket around the circumference on the pump housing. Factor in a deteriorating, old diaphragm, with petroleum degradation added in, inevitable leak. They make a rebuild kit for these. The smaller ones like on the Briggs engines, just replace it.


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## LaSwamp (Mar 16, 2021)

I don't understand what benefit there is in designing the fuel system with a pump when gravity feed would work just as well. Better, since it's one less part to malfunction. It seems overly complicated.


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## iowagold (Jan 22, 2020)

see if it runs ok with gravity feed.
some of the floats are designed for 3-5 psi.
and some are at more up to 10 psi.

modern gx hondas are at that 2-3 psi range.like on the eu2000i. as well as the eu2200i generator
and those pumps would work fine for this application.

gravity feed can be up to 7 psi depending on the tank location to the carb fuel inlet.
on a 1/2 empty tank it is lower so that is why honda likes the fuel pump.


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## LaSwamp (Mar 16, 2021)

iowagold said:


> see if it runs ok with gravity feed.
> some of the floats are designed for 3-5 psi.
> and some are at more up to 10 psi.
> 
> ...


The problem is that the fuel intake on the carb is pointed down. Would the pressure in the line be enough to overcome that?


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## drmerdp (Apr 10, 2018)

One perk of a fuel pump is an extended run kit could be used. Simple fuel cap adapter and marine tank.


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## LaSwamp (Mar 16, 2021)

drmerdp said:


> One perk of a fuel pump is an extended run kit could be used. Simple fuel cap adapter and marine tank.


My friend really just wants to get it running again so he can gift it to another friend who doesn't have a generator. I asked him how many hours it has on in but he has no idea. Apparently, he bought it from his girlfriend's ex-husband so there is no telling what condition it's actually in. The only thing we know is that is appears to be probably around 30 years old. If I can get it running, I'll scope it and see what the power from it look like. I need to track down the fuel leak, though.


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## drmerdp (Apr 10, 2018)

LaSwamp said:


> My friend really just wants to get it running again so he can gift it to another friend who doesn't have a generator. I asked him how many hours it has on in but he has no idea. Apparently, he bought it from his girlfriend's ex-husband so there is no telling what condition it's actually in. The only thing we know is that is appears to be probably around 30 years old. If I can get it running, I'll scope it and see what the power from it look like. I need to track down the fuel leak, though.


I look forward to the scope readings.
Im betting it’s a Jaws sequel, Sawtooth for sure.


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## iowagold (Jan 22, 2020)

i hear the jaws music!!
lol!
cool
take your time on finding the leak.
most of the time they are not too hard to repair...
as long as you can get the parts.

hummm...
any chance of updating the carb???
see if a honda carb will bolt up?


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## LaSwamp (Mar 16, 2021)

I replaced the fuel lines. They looked pretty bad. I bypassed the fuel pump and connected the fuel line directly from the tank to the carb. It still won't start. The carb is getting fuel now, but no joy. Granted, the carb may be flooding. I told my friend that the engine may simply not be designed to work with a gravity fed fuel system. I told him we can try replacing the fuel pump but I don't know if that's going to solve the problem. It's a really old engine and there could be any number of things preventing it from starting. He said it ran when he first got it, but it started running badly and he replaced it. The generator has been sitting up for about a year and a half. 

I did confirm that the fuel pump was leaking. It sounds like my friend is just going to come and pick it up. I told him he may need a professional to look at it. Troubleshooting a generator that old is probably above my pay grade.


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## drmerdp (Apr 10, 2018)

Will it run on starting fluid? I usually start with that to determine if the issue is fuel related.


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## LaSwamp (Mar 16, 2021)

drmerdp said:


> Will it run on starting fluid? I usually start with that to determine if the issue is fuel related.


I don't have any starting fluid, so I wasn't able to test with it. I think it might be flooding.


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## LaSwamp (Mar 16, 2021)

My friend came over and we did some more testing on that old Powermate. He removed the spark plug to see if it was making a spark. It wasn't. We tried another spark plug. It still would not make a spark. That certainly explains why I could not get it to start, even after replacing and rerouting the fuel line. It told him it could be any number of things causing the problem. With a generator that's at least 35 years old, and maybe closer to 40, he really needs to decide how much money he wants to put into it. Even if he gets it running perfectly, the thing is still going to make power dirtier than a Louisiana politician. If he wants to do it as some sort of pet project, that's one thing. I would want something a lot more modern to use if I needed power during an outage. I don't know if it has an AVR. 

He ended up taking it back home with him. At least I was able to fix the fuel leak, for what that was worth.


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## Ground Fault (Jun 9, 2020)

Agreed. It would make a great back-up generator, there only to help you sleep better at night. With acceptable wattage levels available new for less than $500 I don't know how much a person would want to sink into it. If you could get out cheap with only a new coil it might be worth it. Knowing that if your primary suddenly stopped you could get the backup going before the LA humidity and heat woke your wife, a new coil might be well worth the expense. Mine was the same unit, only with a power console instead of receptacles on the bellhousing. It was my front line generator from the mid-80's through 2010. Scares me now to consider what I exposed my appliances and electronics to. Heck that vintage Briggs may be worth more alone, off the chassis!


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## LaSwamp (Mar 16, 2021)

Ground Fault said:


> Agreed. It would make a great back-up generator, there only to help you sleep better at night. With acceptable wattage levels available new for less than $500 I don't know how much a person would want to sink into it. If you could get out cheap with only a new coil it might be worth it. Knowing that if your primary suddenly stopped you could get the backup going before the LA humidity and heat woke your wife, a new coil might be well worth the expense. Mine was the same unit, only with a power console instead of receptacles on the bellhousing. It was my front line generator from the mid-80's through 2010. Scares me now to consider what I exposed my appliances and electronics to. Heck that vintage Briggs may be worth more alone, off the chassis!


I told him it might be a coil problem. That coil is probably the original part. He already has two mostly new Predator generators, so he doesn't need it as a backup. He had wanted to give it to some mutual friends who don't have a generator. Really, I think the friends would be better off not relying on a generator that was new in the box when Reagan was still President.


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