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canuk43

Chain saw won't start

canuk
12 years ago

Hi

Let me start by saying I'm not a small engine mechanic, but I do like to tinker out in the garage and general have good luck with repairs.

My Neighbour brought over his three chainsaws for me to have a look at, non of them running. They all seem to have the same symptoms, they don't start, not even an attempt to start, no pop, no nothing. It actually sounds as thought the ignition is turned off. This is what I have tried so far.

-I have a good blue spark outside of the cylinder, and have tried new plugs.

-Fuel lines seem good and seem to be getting fuel to the cylinder as the plug comes out wet after attempting to start.

-Compression seems good, but only checked with my thumb

-I have tried a shot of ether in the air intake, nothing

-A shot of ether in the cylinder, nothing.

-changed the coil with a know good one, nothing.

When I say nothing I mean nothing, no pop, no burp, no smoke, no heat.

Would anybody have anything else I could try?

Reading some other post on here I am going to check the flywheel keys tonight when I get home, but I wonder what he could have done to cause the same issues with three saws.

I my mind a shot of either in the cylinder should bypass any carb/fuel problems, I have spark and compression, so I am stumped.

Any help would be appreciated!

Cheers,

Ian

Comments (8)

  • rcmoser
    12 years ago

    "I wonder what he could have done to cause the same issues with three saws. " How long since they have been run?? IF they have been setting for while then that would explain why the all have the same problem due to improper storage or setting very long time. This caused the gas to go stale and plug up the carb. Crack the fuel line and even the in tank filter to fall off the inlet hose. I would use carb. cleaner to prime ether Evaportes to fast and has NO lubicrating properties. Basiclly your going to have to do complete fuel system cleanup and inspection if they have been setting for long time 6 months or more IMO>

  • canuk
    Original Author
    12 years ago

    They actually haven't been sitting that long, he used them in the fall is my understanding.
    Even if the carb and gas is bad, I think I should still get a pop, when adding ether to the cylinder.
    I only used either to eliminate the carb and fuel system.
    Thanks!

  • ewalk
    12 years ago

    Ian : In theory ether should caused the saw to attempt to start if enough is sprayed within the cylinder. Cheaper Quick Starting fluids as rc has advised do lack lubricity . Usually I use carb cleaner spray or add a half ounce of mixed fuel carefully poured within the spark plug hole . Give it a try if you indeed have good blue spark and adequate compression the unit should at least attempt to fire . Fuel stored for over 6 mths even without ethanol additive (within Ontario) could be stale and have gummed up the fuel circuits. Let us knw how you make out Dude !

  • canuk
    Original Author
    12 years ago

    I will pick up some carb cleaner for future use, I like the idea.
    I did dump the old fuel and added new stuff.
    I think there is another underlying problem other then the fuel though. There has got to be something causing it not to even attempt to start. Once I get these to fire, then I can see if there is any fuel system problems.

  • ewalk
    12 years ago

    Do not know the origin or manufacturer of the 3 saws bit to have all 3 have flywhell issues is just to much of a coincidence lol . Bad gas and fuel gumming though is common . The carb fuel filter and inlet neddle valves would be the 1st place to start if as stated all units ran well 6 mths ago . The carb diaphrams could also become an issue on older saws , as could inlet needle valve restriction due to dirt or varnish . Keep us posted .

  • loger_gw
    12 years ago

    Ian,
    1. What are the brands and models?
    2. What is your method to check for spark? Do you know you have a good ground and good plugs?
    3. Are you sure of the start positions on these saws?
    4. I got wood from a tree trimmer last week, one helper could not start a saw due to the saw�s multi switch position compared to his he reported.
    5. Have you tried disconnecting a switch?
    Please excuse the level of these questions but sounds like something small is being looked over. loger

  • canuk
    Original Author
    12 years ago

    Hi Loger
    1. I don't have the models but one is a Poulan 16" and the other two are Troy-Bilt 22", One TB is a 46cc and the other is a 49cc.
    2.I checked for spark by removing the plug and laying it on the engine for ground. I have changed the plugs and swapped out the coil on the poulan as it is the same engine as my craftsman.
    3. I followed the start instructions that are on the saw.
    4. If the switch was in the wrong position I don't think I would have spark would I?
    5. Haven't tried disconnecting the switch yet.

    I am thinking it is something silly I am missing also and I agree it's a long shot that all three have the same problem.
    I actually had a brain fart this morning and wondered if maybe the blade brakes are on, would that actually stop them from starting? I will look at that tonight when I get home. But, if the owner of these saws who is familiar with them can't get them to run....

    Thanks all for the suggestions!

  • rcmoser
    12 years ago

    "I am thinking it is something silly" My guess is your priming method. if you want to use the ether (which was designed to start old diesels 10 degrees or colder while cranking them not spraying and then cranking. try spraying it in the carb. while your pulling the rope. Maybe enough will get to the comb. chamber for it to fire off it before it evaporates.

    Probably all caused by the owner not storing it properly or knowing how to prime engines to get them to start when no gas is reaching the combustion chamber. I could imagaine what the bar and chains look like!?!

    How to prime: Pour gas in carb. NO. it's fire hazzard and flooded the engine out wetting spark plug due to unregulated amount you poured in, now it's not going to fire till all the liquid gas evaporates.

    use ether No, but if you have to spray it in while you pulling the rope-this will suck it down to the comb. before it has chance to evaporate.

    Using carb. cleaner: IMO the best way. you can regulate the amount so you don't flood it. And if you do the carb. cleaner evaporates at rate quicker than gasoline, but about 1/2 as slow as ether. Could of use the search for this problem this comes up about every two weeks or so owners not knowing how to start equipment that been setting like weed trimmers, chain saws, tillers, lawnmowers, ect... all seem to have this strange problem also.

    Next: how to clean flooded engine cause I sprayed or poured too much priming fluid in the carb.
    Choke off, throttle held wide open and pull the rope several time blowing it out the muffler and compression evapoating the liquid faster and it may just fire after the spark plug has the liquid gas off it. For extreme flooding remove the spark plug and pull the rope all the liquid will blow out the spark plug hole with ignition off of course. Clean the plug and start over.