Cityboy,
glad to hear the Autozone tip worked out for ya. Im a little concerned about that low of a compression. It should pop but it also is low. 135-155 is a normal ring wear range. I understand you don't have any others to confirm compression guage operation with. Im also surprised to see the shape of your piston knowing you are showing 125psi. I suspected some exhaust scuffing but see none in your pics.
I understand you have a IPL for the saw and not a service manual ??? Im not understanding where you say that the "line connecting the decomp" was cracked. Im thinking you meant the impulse line and if you blocked that off you found a problem if not THE problem. Does that hose you describe connect the carb to the crankcase? If it does it needs to be replaced. Im thinking I am not understanding what you are describing. Maybe some more pics ? definately one of the impulse hose.
stay with us we'll get you through this.
Yeah, considering the shape of the piston I was expecting a better number also. I used a small bungee to hold the throttle open, made sure the choke was off, so I'm pretty sure I was getting good cylinder filling.
I do have the service manual that's commonly available online.
This saw has the auto-decomp feature, which involves a valve coming off the side of the cylinder (where the hex bolt head is now in the picture). That valve has a banjo-fitting on the end with a hose that attaches to a nipple coming out of the crankcase on the other end. The hose was cracked, or at least it came off in two pieces when I tried to extract it from the nipple on the crankcase.
The impulse line isn't loose as far as I can tell, but haven't done much but tug on it with a screwdriver to make sure it resisted that. Also, I'm getting fuel like crazy, so it would appear to be doing its job.
At this point I'm kinda ruling out the ignition timing being off because if anything happened like a twisted crank, or flywheel slipped on crank, the saw would have probably died right then, but the last time I used it nothing unusual happened and I shut it off normally. I could go back to AutoZone and get the flywheel puller, but I really don't suspect that for now.
What seems like the most likely cause now is a weak spark, that's something that I can't rule for sure.
If I'm getting so much fuel that the saw is flooding, I'm guessing that I would at least get it to start, but then maybe run bad, would you agree? If so, I'm going to rule out fuel problems for now too.
How about crankcase leaks through the crank seals? Would that prevent a saw from starting, or just make it run erratic once it started? I'm guessing that would also result in low fuel flow because it can't draw enough crankcase vacuum to pulse the impulse line.
Any and all answers would be much appreciated at this time because if everything else can be ruled out except for the weak coil, I might just gamble the $60 on a new one.
