Have rebuit carb and seem to be getting fuel to cylinder. Get spark when grounding plug to cylinder. Saw will not fire even when using starting fluid (using fresh gas + oil mix at all times). During last tear down to check spark, the plug ignited the fuel air mix being pushed out of the cylinder. I am at a total loss! Has anyone heard of a saw flywheel key shearing and what should the gap between the coil and the flywheel be?
Hi, I just found this site today. My curiousity is killing me now. Is the problem resolved? What is it? Thanks.
This is not really a solution.... I can't post a comment. I think you know where I was going with the flywheel thing - whether or not the timing is right. I thought you'd pulled the flywheel yourself, and sorry, I'm not sure how to pull it. I'm assuming this is a 2 stroke motor... you might want to just check that the piston is near top dead center when the magnet on the flywheel hits the coil..... you can stick a pencil or anything long through the spark plug hole to give you an indication if the piston is at the top of the cylinder or not. Let me know how it goes!
Yeah, this one's a pickle, eh? The fact you said the spark plug ignited the fuel coming out of the hole leads me to believe you're gettinng a good strong spark. You said you've tried QuickStart or whatever, I believe (the spray starting fluid you spray into the carb intake)? I was thinking maybe a reed valve or broken piston skirt, but you say the air fuel mixture comes out the spark plug hole, and the plug will actually ignite that?
I can only think of two things to try at the moment, and I may be way off. Is there a chance that it's flooding? You'd probably know when you pulled the plug, it would probably be wet. you can try disconnecting the fuel feed to the carb and cranking until the float bowl on the carb is empty, and then have someone spray short bursts of Quickstart into the carb intake - it should work with the choke fully open, buy you can try different settings.
The other thing you may want to do is go to an auto parts store where you can borrow a compression tester, and test the motor to make sure you're getting good compression. I have no idea what the specs are regarding compression for this motor, but you can probably make a judgement on it yourself. I would think at least 80psi, and probably well over that.
Good luck, and keep me posted!
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johncaman-thanks-have not pulled flywheel to check key-I assume that it can only be installed in one position. Do you know how I can pull the flywheel without a fancy puller? It is starting to look like that checking the key is my next step.
thanks again
robertwol519
johncaman-thanks again,
I pulled the flywheel and the key is NOT sheared-I do not know where to go from here.
Hope you have some thoughts!
I have check the compression and it is 90psi +.
My only clue that I have not mentioned is that the saw will not even try to fire-except that after to tear downs (including opening up the pump and metering side of the carb) the saw fired a couple revs then stopped. Can you make anything out that?
I also have tried starting fluid (but not with making sure the carb is empty to eliminate flooding-I will try that).
Thanks a lot
The gap b/n the flywheel and the coil shouldn't be that critical - close, without rubbing, and if you're getting a good strong spark, you should be okay. I assume the keyed flywheel can only be installed in one position (not flipped 180degrees, or rotated from the key at all)?
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