# Coleman Powermate Vantage 3500 Generator Dies After Short Few Minutes



## mikulskn (May 28, 2018)

I inherited a non-working Coleman Powermate Vantage 3500 generator that consistently dies after running 3 minutes after engine is cooled down. The Coleman model number is PM0473503 and the Briggs & Stratton engine model number is 115432.

When the unit is cold, it will start right up and run for about 3 minutes. It does NOT sputter and just dies. It consistently does this. When it dies and I wait 30 seconds, it will start up and run for a much shorter time, like 30 seconds. The longer I wait after it dies, the longer it will run before dying again.

I initially thought it was a fuel problem, but I have cleaned the carb twice. I checked the fuel lines and fuel filter, and fuel pours thru the line. I cleaned the main jet thoroughly and the needle/float, and fuel readily comes thru the needle. 

I thought maybe not enough fuel was entering the carb thru the needle, but I was able to check the fuel level in the carb when it dies. The fuel line has a shutoff valve. So I was able to check the amount of fuel in the carb when the unit sat for a long time. I did this by shutting off the fuel valve, then drain the carb fuel and measure the amount. I then would open up the shutoff valve and start the unit. When the unit dies, I immediately shut off the valve. Then I drain the carb and measure again. The amount of fuel is the same at this point as when the unit is cold, so I know the carb bowl is full when the unit dies.

I eliminated the vapor lock issue by trying to run the unit with the gas gap off. It still dies like noted above.

I also changed the spark plug.

It appears the unit does not have an low oil sensor, so a bad oil sensor cannot be the issue.

Based on all the above, I am thinking it is heat related due to the consistency of it dying. I am also thinking it is not related to fuel due to what I described above and that the unit just dies instantly with no sputtering. I am looking for any ideas on what the issue could be or what to troubleshoot next. Thanks!


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## tim4 (Jul 6, 2014)

When it dies check the spark and if no spark maybe there is a mouse nest under the shoud by the coil causing the coil to heat up and fail. Take the shoud off and clean the engine around the flywheel area and fins.


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## 36984 (Apr 10, 2020)

mikulskn said:


> I inherited a non-working Coleman Powermate Vantage 3500 generator that consistently dies after running 3 minutes after engine is cooled down. The Coleman model number is PM0473503 and the Briggs & Stratton engine model number is 115432.
> 
> When the unit is cold, it will start right up and run for about 3 minutes. It does NOT sputter and just dies. It consistently does this. When it dies and I wait 30 seconds, it will start up and run for a much shorter time, like 30 seconds. The longer I wait after it dies, the longer it will run before dying again.
> 
> ...


So, what did you find???


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## 36984 (Apr 10, 2020)

I have the exact same issue. Im certain there is a low oil sensor, but im betting the oil viscosity is too low and unit is overheating. I think it should be 30 weight oil in there?


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## speedy2019 (Jan 29, 2019)

Yeah it does sound like something is getting hot


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## iowagold (Jan 22, 2020)

yea check the coil for spark.

but more than likely it is the fuel cap not venting...
try leaving the fuel cap loose and see if it runs ok then...
or when it quits, loosen the fuel tank cap to see if there is a sucking sound.
some have changed out the new modern carbon caps for the classic caps to stop this...
or have added a marine fuel tank vent.

on the late model generators 
just watch the fill on the fuel tank, an over fill on the tank is what starts this issue...
if you have a honda generator or other brands with a flip lever for the fuel tank vent on the cap..
these can be serviced and cleaned if the rubber seal for the vent has stuck.
just carefully take the cap apart (they are spring loaded on the parts) and clean all of the rubber and surfaces.

this also goes for the fuel systems with an extended run "BERG" or marine fuel tank fuel system.
make sure to open the tank vent on the marine fuel tank.
the berg system relies on suction from the primary generator fuel tank. so I sucks fuel in to the tank from the external marine tank that has to have a vent open to work right.
I have parts etc listed in the poust usa site as well as in the honda generator forum
in the extended run section main groups.io Group

try running with the fuel cap loose and let us know if that fixes the issue!
you can also just replace the fuel cap with a stock cap..
just keep in mind that they can fail over time to vent properly.


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## iowagold (Jan 22, 2020)

oil should be 10-30 in most all gasoline engines.
make sure the level is right.
check the spark with a spark tester
see this link for a set of tools list for generator testing
get the spark tester asap unless you have one!!





ENGINE_TEST_EQUIPMENT


engine test equipment



www.poustusa.com




click here for generator test gear
but check the fuel cap!! 99% of the time it is the cap.


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