QuestionQUESTION: Coleman Powermate 4000 runs it self out of fuel in the fuel line...have taken the insides out of the fuel cap(no possibility of vacuum, cap is venting)New fuel line,new fuel filter, no vapor lock(built a small heat shield to test that), new in tank filter screen, also tried with in tank screen removed same problem...have ran this thing on a daily basis for over two years with no problem, than all of the sudden this running out of fuel problem started and like I said its in the fuel line not the carburetor...oh, did I mention this is an intermittent problem sometimes it will do it several times in a row then run fine for days in a row then on day it will start to do it again sometimes for a couple of days then not at all for several days...ambient temperature is not a factor as this has been going on for about a year and half, hot, cold makes no difference...when it is acting up you can stand there and watch the fuel filter go dry, the engine will quit, then you can watch the filter fill up, when it fills you can pull the rope and off she goes maybe for 5,10,15,minutes maybe days...any ideas???
ANSWER: Did you connect an axillary fuel tank to the unit and see if the problem still persists? Did you change the fuel line?
Once had a similar problem but it turned out to be a bad fuel cap which allowed a vacuum to build inside the fuel tank...took me several weeks to troubleshoot.
Eric
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QUESTION: no,I've thought about it(the auxiliary fuel tank)it really seem to me that the problem is in the tank though, I did put a new fuel line though and I pretty well have ruled out the fuel cap as I have have taken out all the insides and now have a small hole in the cap with nothing blocking it (you can see light through it... I got to wondering if there was a way the fuel shut off could have a piece of junk in it that sometimes wiggles into just the right spot and causes a partial restriction...I've had it off and looking at it,it seemed to be OK..but it is the only part I haven't changed yet...if that doesn't work then I'll try the fuel aux fuel tank... is it possible that the fuel cap (if working properly)would create a positive fuel pressure as well as vent the tank???
ANSWER: Most of the time the fuel shut-off either work or don't work...rarely anything in between. As for the fuel tank creating positive pressure, the anwswer is yes. However the positive pressure rarely has any effect on engine performance.
You can use any type of container for an auxiliary fuel tank. It just has to have a fuel nipple, hold fuel, and be placed above the carburetor inlet nipple.
Are you sure the problem is fuel related? One way you might rule out fuel is to use a primer, starting fluid, gas from a small squeeze bottle, and prime the engine directly into the carb when the engine stops running. If you can keep the engine running while priming then you know for sure it is a fuel problem.
Just for kicks, have you checked the valve clearances?
Eric
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QUESTION: no to the valve clearances, but the problem definitely is fuel supply related because when this thing starts acting up you can start it back up and stand there and watch the fuel filter start to slowly lose volume until it is empty then the engine, of course, stops running. As you continue to watch the fuel filter will fill back up, you pull the starter rope and varoom, off she goes purring like a kitten until another cycle of these events occurs maybe minuets, maybe hours, later. I just don't see how the engine itself would cause these occurrences...Can you??? As for the fuel valve idea that's what I thought, either good or not, but I couldn't and still can't come up with any thing else... I'll try the aux fuel tank next(just for kicks)...Thanks. Kenneth L.
AnswerAn old mower fuel tank, the plastic tanks with the fuel nipple, is all you need for an aux fuel tank.
Try your local mower repair shop and ask for a POS used tank. If the shop wants money I would not pay more than $5 cash...anymore $$ then I would walk out and find another shop or look for a friend who has a mower with a plastic tank. May Craftman mower with Tecumseh engine reqire no tools to remove the tank....just loosen the hose clamp, lift tank and remove.
Let me know what you find so I can update my kwowledge base and provide some help if you need.
Eric
