ok guys, this one has me stumped.
my fs45 was running great one day, went to use it a few days later(we've been having hot and wet days so the grass is growing crazy fast) and I couldn't pull the rope. it would hardly budge. after a few minutes attempting to get it to crank over, I finally got a full rotation, when suddenly fuel came gushing out of the muffler, which then continued for the next 5 minutes or so till a beach ball sized pool of fuel was on the pavement.
took the carb apart, all looks fine. still couldn't get it to start(even after multiple days of attempts, with the plug out and covered so the cylinder could vent and not get dirt in it) bought a new carb from the local dealer(I did just put a new fuel mix in it, amsoil 100:1, as they recommend that for 50:1 equipment, and I'm a huge believer in amsoil) so figured maybe the richer fuel(also, I use 110 race gas as i already use it for a lot of other equipment, and its the only place i can get ethanol free gas. DOWN WITH ETHANOL!!!) needed an adjustment range beyond what the factory carb could do with the plastic lock tabs. after about 10 pulls when I pull the plug it is dripping with fuel.
today is day 9 of no start. I decided to completely gut the thing to see if there was any noticeable damage, or any reason for the machine not starting, and I couldn't notice anything. everything is actually very clean, and no signs of excessive wear. I was given it by my grandfather who is just not wanting to pull start anything anymore, and was used very seldom. piston looked good, rings looked good, weren't cracked or anything, and they moved in and out freely. I am pretty familiar with stihl products, just not "factory trained" but i have taken a few courses.
I do get spark, and my kill switch is functioning.
I have 5 foreseeable courses of action (COA from here on out).
COA 1: I see a pulled short block(no carb or muffler) on ebay for about 35 bucks. take the gamble in it actually functioning? It claims to have been pulled from a working unit.
COA 2: replace the coil pack. possible weak spark? gamble on that not being the fix.
COA 3: Replace piston and cylinder. Maybe I'm getting low compression? I don't have a gauge, but it feels good pulling on the rope. but that doesn't tell much. Now, I may get a little weird with this. Are there any larger bore pistons and cylinders that would "fit"? If im gonna be replacing it, may as well do it Tim Taylor style, right?
COA 4: both 2 and 3, possible that I have both problems compounding on each other?
COA 5: take it to the dealer and let them fiddle with it (had they been open Saturday afternoon, they would have it now, but, that didn't happen) I'd prefer not to take it in. Not because I don't trust them, but because well, I'm slightly embarrassed about it. I took out the spark arrestor and drilled out some of the baffles to get a bit better flow, which will result in needing a richer mixture, and probably less efficient running, as more fuel will be escaping out of the now free-er flowing exhaust system.
me personally, I'm leaning towards 4, because... why not?
your opinions?
fs45 wont start
