First try the sparkplug gap trick. When voltage is low the spark cannot
make the large jump. Decreasing the jump can get a small spark through.
Usually, any spark that can jump the gap (when installed in the
cylinder) will run an engine, although it will not run well at low loads.

I assure you that if you pull the flywheel/magneto off you will
immediately see the condenser and the points. You cannot really check
the condenser. Check out the points for being properly adjusted
(gapped), and pitting. If this were my machine, since I'd gone through
all the work of getting the flywheel off I'd replace the condenser and
points regardless of apparent condition.

I'D ALSO REPLACE THE FLYWHEEL KEY SINCE THIS HAS CAUSED SIMILAR PROBLEMS
FOR ME IN THE PAST. If the key is partly sheared then the spark timing
can get messed up. The key can partially shear (without completely
breaking) if the blade stops very abruptly, like when hitting large
rocks etc.

HTH

EJ in NJ

93JONK wrote:
On Dec 11, 12:53 pm, Ernie Willson wrote:
It could be that the ignition system is not up to voltage. There are a
variety of reasons for this as mentioned by others here. I'd try closing
down the spark gap to a minimum (say 0.010 inch or less) and trying to
start it again (at full or near full throttle). If it starts then you
should look into fixing a weak ignition system. If it doesn't start then
(most likely but not certainly) your problem is not with the ignition.

EJ in NJ



93JONK wrote:
All right, here goes..... i bought a 1986 Toro Lawn tractor on ebay
for quite a steal. Briggs 11HPi brought it home and stuck my jump-
starter on it and got to work. at first it obviously would not fire
up. i tinkered a little and could get it to fire up off of starting
fluid. at that point i started checking the gas lines, which were
clogged. i cleared the lines and tinkered with the carb for a while
and i eventually got it to fire up off of gas, but could only get the
engine running with the throttle up high. but it ran!!!! i rode it
around my property for about 10 MIN but it would still only run with
the throttle up high. the engine sounded great with no knocking or
sputtering. i went inside and ate dinner and when i returned (about an
hour later) it wouldnt even fire off of starting fluid. NOTHING. i
figured that the motor was flooded and i knew the carb needed
cleaning, so i removed the carb, drained the oil, and took the plug
out to hopefully clear some gas out of the chamber. that night i
cleaned the carb. the next day i re-filled the engine with oil,
reinstalled the plug, and cranked the motor a few times w/o carb to
hopefully clear any remaining gas out of the chamber. i reinstalled
the carb, but did not hook the gas line up to it. i gave it a squirt
of starting fluid and NOTHING. i can hear that the motor has
compression. and the plug is not wet, so at this point i dont think it
is flooded. i checked and i get a strong spark (ouch) from the wire to
the engine, but i cant seem to get a spark between the contacts on the
end of the plug when the wire is attached to it when i ground the plug
to the motor. i know the plug is good, because i tried it in my
snowthrower and it worked great. i am pretty sure that it is something
simple, seeing as though i had it running, but i am out of ideas.
please help!!- Hide quoted text -
- Show quoted text -

it's not a bad plug, because i checked my snowthrower and this plug
fires it up no problem. i picked up a new armature for cheap, and i
will see if this fixes the problem. also, i will try closing the gap
on the plug. from there i guess i will take the flywheel/magneto off
and check the points and condenser, but what am i looking for?