Can't get it started. Was working a month ago.
Briggs & Stratton 3.5 HP
Oil is good
Air filter good
Replaced spark plug cleaned wire
Two adjustments I played with but don't know what they are? Allan key ..
and flat head screw driver adjustments.
Can't get it started ... what do I try?
That's a built in safety mechanism so you don't beak your crankshaft. A ten
cent aluminum key. If your blade hits something, the inertia causes the
weakest part to bend (the key). This changes the timing enough so the engine
won't run. I know of what I speak. I attended the Briggs & Stratton small
engine repair classes many years ago and worked as the service manager of a
repair facility. There could be other problems, not saying it's the key, but
I picked up a mower that wouldn't start last year for $5 because the
body of mine was rusted. Swapped motors, and recently gave the old
The guy who got emailed me back (I'd asked him to let me know) to tell
me the key was broken and that's why it wouldn't start.
He got a great deal, I got a lump of metal out of my shop so everyone
The fellow I got it from told me he was using a de-thatching blade when
it stopped running, so your diagnosis makes perfect sense to me.
How do I find this bent key? ..... I won't find it taking off the blade
right? .... Is there a manual online .. cause I have no idea where the
flywheel is or more importantly where the key exactly is ???
First thing is to check for spark. Pull the plug wire off, put a screwdriver
from the wire to ground but leave a 1/4 inch gap. When you pull the rope, a
spark should jump the 1/4 inch gap. No spark, it probably isn't the key. If
the key is bent, you'll still have spark but the timing will be off. The
flywheel is under the shroud. At one point on the shaft there is a slot and
at that point the flywheel slot should line up perfectly. If one is off from
the other, the key is bent. Getting the flywheel off requires a puller or
else you'll damage the flywheel. I'd suggest the manual if you get in this
deep. If you were not cutting rough stuff and didn't hit any rocks or tree
branches before stopping the mower, then it probably isn't the key. Someone
else suggested using starter fluid available at an automotive store and
that's a good suggestion, cheap and easy. I think the manuals are available
directly from Briggs & Stratton or through one of their dealers. I've also
seen their small engine servicing course but that was a few years ago. No,
you don't take the blade off to change a key, long day, my tired brain
Un"fix" the adjustments. Check for spark. Make sure the blade is
on tight. (It is part of the flywheel for some models.) If it
sparks but doesn't fire, squirt a little gas into the carb and
try again. If that works, it is a fuel problem.
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