My portable generator ran fine for 5 hours, then ran out of gas. I refilled the tank but now the pull is excessively hard and the unit will not start. I removed the spark plug and the pull was normal.

What next?

  • Please describe more about after the spark plug was pulled out. For example, it should be really easy with it out, easier than when in place before the trouble started. Then you put it back in and pulled it was normal? or is it excessively hard again when it is replaced?
    – Jack
    Dec 10, 2013 at 19:38
  • You have enough oil in the engine? It could something screwed up in the crankshaft. In other words it sounds related to the engine and it doesn't sound like a problem with the pull. Dec 10, 2013 at 20:22
  • Check the intake and exhaust for any restrictions. 2 stroke Engines are fairly simple, air/fuel mix in, exhaust out. Check for sticking valves, or blockages. Including the make and model number of the generator might be useful.
    – Tester101
    Dec 13, 2013 at 12:03
  • Mine is the same but I was using 95 octane fuel should have used 91. may have over heated??/ Just guessing
    – user54256
    May 22, 2016 at 12:51

4 Answers 4


Mine is doing the same. I fully disassembled after checking the easy stuff. The decompression lobe on the cam is no longer functioning. Mine needs a cam.


Mine is hard to pull even without spark plug and I took the thing apart and when I disconnected a plug that leads to the electrical parts it was easy to pull so I plugged back in to see if it was the reason and it was cause when it's not plugged it it turns fine but when I plug that back in it's hard again. I'm assuming there's a clutch of some sort that engages when it starts but is malfunctioning. I'm assuming it's supposed to disengage when stopped and engage after the engine starts


Could have been a compression problem which got worse because there was no ignition. That's why some chainsaws have a push button on the cylinder-head to relieve pressure in the cylinder, which makes it that much easier to start them. (otherwise with each pull the compression gets worse and therefore the pulling gets a lot more difficult)

  • 3
    That would not be it. Engines do not accumulate compression with each pull. Any built up compression from failed ignition is released at the end of the cycle. The decompression valves you refer to act to reduce the compression level of each cycle during the starting procedure, it does not relieve built up pressure from previous cycles.
    – bcworkz
    Dec 11, 2013 at 23:03
  • It obviously has something to do with compression, as it's only hard to pull when there is compression.
    – Mazura
    Feb 24, 2016 at 5:28

I have come across this problem on Multiquip generator/welder combo. After talking to a representative from the company and doing some electrical diagnosis, the problem was the transistor PTR. If I removed the generator section from the engine, the engine started right up. I put it back and it feels like someone is holding the output shaft, lots of resistance in pulling and could not start it. After the new part was put in, it started right up. The tech said it creates something along the lines of a "electromagnetic gate" the resistance in pulling starting is created from parts of the generator acting like a magnet. Hope this helps some of you. The part was very expensive by the way, I think it was either $400 or $600.

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