Question about Coleman Powermate Premium Plus 6250W Portable Generator

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Coleman 5500 (MZ300)

I purchased the generator two months ago and ran it for 30 minutes then shut it down. Recently I attempted to start it and it will not start. I have fresh fuel and the oil is full. I'm at a loss as to how to start it.

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  • Anonymous Sep 05, 2008

    have changed the oiland that's when the shutting down after thirty or fourth minuties started. Any ideas?



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My answer:

Almost 90-95% of all the Genset problems found by the factory approved Genset Service Centers are related to the fact that people don't read the OWNERS MANUAL first, and just didn't put OIL in the Genset (or the right amount) - as they are shipped from the MFR without OIL in the units to begin with!!!! (See esp #3 and Final Notes below as well)

And here I thought everybody KNEW THAT!!

I guess sometimes you just have to ask the most OBVIOUS ??'s first huh (dumb as " it " may sound)?

If you bought your Genset from other then a Home Depot Store, and it's still under warranty - then you will have to contact that outlet, and see what they have to say or hopefully can do for you.

Esp all those Gensets that are Made in China and have flooded the USA market in the last 10 years or so - no thanks to our representatives in WASH DC that's for sure. It's a wonder this country even functions with all this "inferior" Made in China JUNK that keeps prematurely failing before it's normal time. Sad to say the least!

Some other obvious things to CHECK for that may be the cause of a NO start condition even after adding proper gas & oil to the brand new Genset:

1 - Some Genset gas tanks come with a gas cap "blocking insert" under the gas cap that should be removed according to your manual if it states this. (Read manual section on "First Time Starting")

2 - Is the gas tank shutoff valve FULLY OPEN? By the same token (even if the Genset is or isn't brand new) does it have an in-line fuel filter anywhere in the gas line? If not then esp read #5. Always check as well the AIR FILTER for proper cleanliness (if oiled type), or clean appearance if it's a paper element type. Clean or replace as needed!

3 - Is the RUN SWITCH set to ON or RUN position (this is purely an "Electrical ON-OFF Switch" usually a single-pole single-throw type btw, and it can go bad with high usage)? Does it move freely from OFF to ON? Is it working properly? Test it using a known good quality DVM or OHM meter! It's contacts may have become tarnished just from sitting around too long? Esp where you have saltwater conditions in the surrounding air! This switch actually & electronically is wired in REVERSE so that when switched to the ON position the wired contacts are OPEN thus letting the Ignition Coil fire for SPARK. When switched to the OFF position the wired contacts are now CLOSED thus connecting (or switching) the "Control Board" logic voltage signal (usually anywhere from +3 to +12 VDC upon start-up) to GROUND - thus cutting the RUN voltage to the Ignition Coil fire - as in SHUTDOWN. On some model designs there also may be a separate IDLE CONTROL SWITCH and POWER REGULATOR BOARD for better POWER LOAD self-regulation depending on constant variable loads placed on the Genset as related to the work-site demands. If there is NO VOLTAGE OUTPUT but yet good engine RPM function - then I would look at this part first and then #8.

4 - Is the choke being set to the proper position with or without using Ether spray to the Carb?

5 - Does the Carb have a Yellow or Black wire coming off of the bottom of the Float Bowl? This goes to the GAS CUT OFF SOLENOID mounted in the Main Jet inside the Float Bowl. NEVER CUT THIS WIRE as some know-nothings have suggested here and elsewhere in postings, as there are better ways to test the solenoid without doing that! If equipped with one - This anti-dieseling solenoid has to work properly or else flooding will occur with the gas shutoff valve OPEN.

6 - VERY IMPORTANT - Is the Carb Float stuck in the CLOSED position not letting gas into the Main Jet? If the Genset is brand brand new and truly has never been fired up even once and used, such as like that of 2-3 years or longer from actual date of purchase, then that Carb Float may very well be stuck CLOSED. Worse yet - the Main Jet may be clogged with MICRO DEBRIS coming down from the new gas tank - esp if there is NO FUEL FILTER present in the fuel line. I've heard of this happening more then just a few times myself. You might try and TAP CAREFULLY on the bottom or side of the Float Bowl with a hard rubber hammer first to try and see if you can dislodge the stuck Float inside. If there is that colored WIRE (see #5 again) at the bottom of the Float Bowl on your model - DO NOT HIT THAT GAS SHUT-OFF SOLENOID WITH THE RUBBER HAMMER - as you WILL damage it! If this dislodges the stuck Carb Float to the point that the Genset now wants to run to some degree better then before, but not fully 100% better and to spec - then you definitely still have Carb Float and/or fuel delivery related issues, and/or MICRO DEBRIS in the Carb Bowl or Main Jet inlet. If the Genset begins to run great - as it should - and continues to do so - then your NO FUEL or NO RUN problem is solved! I would still take the Carb Bowl off and clean out the whole Assy there just as an added precaution anyway as you just never know. When Gensets are truly needed in an emergency condition you just don't want to RISK anything!! NEVER FORCE ANYTHING EITHER!! It's possibly that you might have to loosen slightly, and/or totally remove the Float Bowl (usually 2 screws) to see if indeed any gas is getting inside to the Float at all. If gas comes out readily but still no gas is getting into the Main Jet and intake then you purely have a DIRTY CARB issue and nothing more! If you're not smelling gas through the air filter box then you are FUEL STARVED. ALSO - Many a brand new shipped Genset will have some kind of NEW gas tank (usually metal gas tanks only) MICRO DEBRIS inside the tank itself or even in the rubber gas line (I've heard of this problem before, and seen this myself 100's of times with cheaper rubber hoses). That is why an added in-line FUEL FILTER (if your Genset has none) is SO important!! Usually a common $2-3 item at any auto parts store. Once gas is added to the tank all this micro debris is set free to enter into the CARB FLOAT BOWL, and that is where Carb problems will start - even with a "brand new" never run before Genset!!

Posted on Sep 10, 2008

  • Anonymous Sep 10, 2008

    PART 2

    7 - As dumb as this next ? is to ask I have
    to ask anyway -
    Are you
    getting GOOD spark at the spark plug? Again - see #3 AND check the
    engine OIL LEVEL as well. The LOW OIL sensor is actual another ON-OFF
    type switch and if the level Some units ship with the spark
    wire cap disconnected and it may look like it's on the plug, but in
    reality it really isn't fully connected! If you are getting a good
    spark then it's highly unlikely that the Maintenance-free
    Magnetron® electronic ignition would be bad. Fouled
    spark plug - YES - bad Maintenance-free Magnetron® electronic
    ignition - hardly.

    8 - If your Genset is used and said to be ? years old, and it just indeed
    might have some high RUNTIME HOURS on it - it just could very possibly
    be what sounds like to me (and I personally HAVE SEEN this
    happen myself firsthand) that the generator brushes are nearly shot
    - as in almost worn out. They may be getting too too hot - as from
    excessive current draw at point of contact, and thus the generator
    sensing circuitry itself is doing an electrical CUTOUT!!

    An added protective Genset "Control Board" circuit feature - that may
    or may not be built into your Genset - is one that is in the Generator
    Head circuitry itself and
    may indeed be linked to the engine as a type of REV LIMITER or CUTOUT
    on the Maintenance-free Magnetron® electronic ignition.
    Just depends on how sophisticated and expensive your Genset is? Thus
    protects by preventing RUNAWAY and OVER-VOLTAGE conditions rare as that
    may be by today's BETTER designed Gensets (DOES NOT include the cheap
    made in China junk). Again - read your operators or service manual as
    it should have a pretty good
    troubleshooting section in it unless you don't have that anymore or
    never got one if you bought it used to begin with.

    If you unscrew & remove the Generator brushes for servicing yourself, and they are indeed
    below the recommended length (or worse case they are indeed totally
    worn down) then that most likely is your starting or output problem right there. If you are having Output problems as well.

    If you choose to replace the old brushes with new ones yourself - be
    very careful when seating the new ones - as to their insertion and cap
    retainer tightening. Never over-tighten those black plastic-like brush
    retainer screw caps - for if you break one (hard to get immediate
    replacements is why), or fracture one it could cause the Genset to fail
    under LOAD, and that very well could do some severe damage to the
    generator part itself. Take your time doing it, and be patient!!

    It has to be one of the CHECK scenarios listed above, as I've covered every
    possible cause short of a broken wire somewhere - which in that case
    you will have to schematic trace and DVM or Ohm-meter out wire to wire contacts.
    This being the least likely scenario from experience.

    If you indeed find the Float Bowl assy to be the cause of dirt
    contamination or varnish build-up clogging the Carb, and you need a
    walk-through of taking it apart, cleaning it out, and then
    re-assembling it again - as well as re-adjusting the fuel mixture Adjustment Screws - just give me a shout here, and I'll walk you through it step by step.

    Final Note: For all older used Gensets - Are you starting and running
    the Gennie for at least 10 mins every month (30 days) as required by
    most all Mfrs? Are you also keeping & running a good FUEL
    PRESERVATIVE/STABILIZER (as required) in each tank of gas no matter how
    often you run it? BEFORE you totally shutdown your Genset after running
    it (even those short 10 required mins every month) - are you first
    shutting off the gas supply completely, and then running the Genset out
    DRY from as much gas from the Carb Bowl and gas line as you can? Even
    though some "so-called" experts tell you not to do this - if you are
    NOT going to be running the Genset every 30 days or plan to store it
    for more then say 6 months at a time - THEN DO IT RELIGIOUSLY -
    otherwise you will VARNISH the Carb with contaminated GUNK buildup from
    STALE GAS! Happens all the time! Changing the DIRTY OIL frequently and
    adding the proper level of 10-30 (recommended), or 10-40 oil is VERY
    important as well. Your engine will use OIL esp if it's older with
    "higher run hours" on it. Keeping a good Maintenance Log makes GOOD
    SENSE as well. You
    should be doing all of these things as well - if you want a smooth
    running Genset when that real emergency does come up, and that Genset
    absolutely has to work 100%!

    That's about all there is unless you got a truly Defective Genset right from the start. Next stop - Home Depot!

    Best regards to all with the same problems, and hope I helped you out 100% - all political humor/truth aside.

    Please post me a reply as to finding this solution being the best
    resolve to your Genset problem there by following my recommendations
    above. Also please rate my troubleshooting fix as well.

    Keep me posted and I'll follow up as well.

    Best regards,




If the oil is dirty, it will not pump properly. I recently had this problem, once I changed the oil it was good to go.

Posted on Sep 02, 2008


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