Have a Poulan leaf blower model BVM200VS; s/n 10238N601820-2 : 10:42 that will not even try to start. Read many online discussions with no luck. Fuel mix is good, emptied tank and put the fuel in chainsaw and the saw started no problem, refilled blower with fresh mix. Changed spark plug, checked gap at 0.027 inches. Both air filter and exhaust spark arrestor are clean. Checked cylinder head mounting screws and they are tight, no evidence of leakage at the gasket. Follow the exact starting sequence as shown on the cover. Checked compression and originally had about 65 - 70 psi, soaked cylinder twice overnight through plug with Marvel Mystery oil and compression is now at 95 psi. Cylinder and piston ring look good through exhaust port and spark plug hole. Carb was replaced with new carb, and then after many other attempts went back to original carb, no help. When trying to start notice fuel mix at exhaust and on plug, remove crankcase cover and fuel mix is evident below piston. Primer works. Putting fuel directly into cylinder does nothing. Starting fluid does nothing. Originally spark looked weak, new coil installed with gap at 0.013 inches and produces nice spark with plug out, spark tester shows spark. Noticed slight air leak at plug sealing washer, polished seat and used new plug with fresh crush washer, this eliminated leak. Kill switch showed funny resistance readings when checked, entire switch and wiring removed to eliminate possibility of intermittent ground. Several comments on compression needing to be at or above 100 psi, my readings are somewhat lower but the engine doesn't even try to start. Any ideas???
Well you certainly have tried a great deal of things, your compression is fairly low, however I would expect it to fire all be it not run too well, initially I would suspect a couple of things, a massive air leak i.e. crankshaft seal leaking or has fallen out, or the flywheel key in the flywheel has sheared knocking the ignition timing way out.
SOURCE: Poulan saw will not start
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!
SOURCE: Chainsaw will not start
Remove muffler and check for carbon blockage.
If that is ok check crankshaft seals for leakage.
SOURCE: 46 cc Sears/Poulan chainsaw will not start
Four things I can think of:
1) There is a short in your spark plug wire. When you bend it to connect the plug in the machine it allows the exposed cable to contact the engine block. Examine the wire all the way to the coil.
2) Flywheel key is sheared ( you obviously know how to take off the flywheel since you checked the seals).
3) Flywheel air gap is not set correctly. Loosen the coil. Put the cover of a notebook or the cardboard piece of a cigarette pack between the magnetic portion of the flywheel and the coil. Tighten the coil down. This will get you the proper gap.
4) Your cylinder/piston or rings are scrubbed out. Even though it passed a compression test, on rare occasions it will loose compression only when it fires. So do the following:
Remove your exhaust manifold. Look into the cylinder with a flash
light. You are looking for scratches. Anything larger then a light
fingernail is definite proof you need a new cylinder/piston assy.
If it passes that test do the following:
Pour
mixed fuel straight into your cylinder until 1/4 full. Slowly pull your
saw over while looking into the cylinder. If you see bubbles after the
ring/rings go by then you need a new cylinder/piston assy. On rare
occasions if no scratches are present on the cylinder wall or piston,
you may be able to change just the rings.
First if you can get a inline spark tester so you can see if your getting spark with the plug installed.
SOURCE: husqvarna 51 died and wont restart
hi
if you have a good compression,a strong enough blue spark and carburetion for the fuel air mixture try priming the engine(put small amount of gas in the spark plug hole)then start the engine.If the engine runs only the gas you put inside the cilinder there is a carburetion problem to find and fix.
let me know regards savumihai71
As you have done most things regarding fuel system i would have to assume it either has not enough compression, or the ignition timing is out, so remove the muffler and check the condition of the piston face through the open port, any signs of scuffing or marking on the piston then the saw has seized at some time and the piston ring is stuck in, if all appears ok then remove the flywheel and check the key has not sheared, the key is alloy and is part of the flywheel..
Testimonial: "Thanks for the information I will try it tomorrow thanks again."
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