Yeah, I've got an old Alis Chalmers Rotary Tiller that I am debating
on whether to fix or not. I had not used it in a couple of decades and
my nephew took it a few years ago to try to get it going. When I got
it back, it is missing the gas tank and air cleaner and I am thinking
I just might as well replace the carburetor. I checked on line and the
gas tank is about $70, the air cleaner is about $35 and the carb would
be around $130.
That's about a third of the cost of a new one but If I get this thing
going and take better care of it and use it more, I bet it would last
me for as long as I am able to use it.
When I was a kid, I discovered that a lawnmower engine would run
on Liquid Wrench. Of course there are carb cleaners that a motor
will run on while cleaning things. I've had luck with spray cleaners
that have the extension tube using it to blow open the tiny ports in
On Fri, 30 Apr 2010 09:30:21 -0500, The Daring Dufas wrote:
When I was a young lad I found out a horizontal shaft Kohler engine would
run on propane from the unlit nozzle of a propane torch held in the
carb venturi. Also found out the motor could easily over-rev and bust the
connecting rod if you fed it too much propane. :)
Someone comes to me for a job and tells me they have a lot of
experience. I ask them: "How much equipment have you burned up?"
If they answer none, I tell them: "You obviously have no experience,
I need someone who has already burned up thousands of dollars in
equipment because I can't afford it. A learning experience can be
Now, that sounds like the voice of experience. I knew a kid
one time who ran an ungoverned lawn mower to get to town and
back. A couple times, until it over revved, and broke.
We recently had a thread about getting home on paint
thinner, when the gas tank was near empty. I've heard gas
engines run well on a spray of WD-40.
It runs just not under load right, ive had several 4 motors like that
and it was electrical. One a bad wire, two the ignition module, one
the coil. A motors spark at idle needs not be strong to run, but to
ignite alot of gas for load it needs to be strong. That doesnt rule
out low compression or a carburator-fuel issue but since it runs it
could be electrical. Is the spark small and weak and maybe red in
color, but ive had small blue sparks not enought to go past idle.
Sears sells a 4$ induction tester you just touch the wire while its
running, if the spark is what dies as you load it you should be able
to see it, and squirting gas in the carb with throttle open should
help rule out or confirm a fuel issue. Why did you pull the head?
On Fri, 30 Apr 2010 10:27:53 -0700, ransley wrote:
No, not running at all. I've had it run maybe a couple of revs under its
own power a few times, then it dies on me (it doesn't seem consistent
though - if it fires like that, I can leave the throttle in exactly the
same spot and come back to it a few minutes later, and it won't fire at
Just to take a look at the valve seats & cylinder bore - only takes a
couple of minutes, and I wanted to make sure the valves looked like they
were seating properly and the bore wasn't trashed for whatever reason.
All appeared OK, though.
On Fri, 30 Apr 2010 11:06:16 -0700, "Jon Danniken"
Also check the gap before install. Those plugs gapped at the factory
are not always accurate... Get the correct heat range for the plug as
they are not all the same :)
OP - loosen the gas cap a turn or two. If the cap vent is clogged the
tank will create a vacuum, affecting fuel flow. Clean vent with a
You have plenty of oil in the engine, right. If the motor has a low
oil kill switch that would shut the down engine.
On Fri, 30 Apr 2010 22:14:44 -0400, Stormin Mormon wrote:
Yep - I was just ruling out a governor problem by manually holding the
throttle (just in case the governor was screwed and trying to throttle
things way back before the engine had chance to cough into life)
Is there a fuel shut-off solenoid inside the carb?
It sounds like you are getting fuel to the carb, just not through the carb.
Sticky float plunger, clogged passages, or partially functioning fuel solenoid
are the usual culprits.
B&S engines have fixed timing.
A partially shorn shaft key might goof up the timing a bit, but the engine
should still run if it fires at all. It's an all or nothing kind of thing.
Concentrate on the carb.
On Fri, 30 Apr 2010 15:22:03 -0500, The Black Knight wrote:
No... I'm not sure who made the carb, unless B+S rolled their own. It's a
pretty simple beast really.
Well, *something* is getting through because I can pull the carb off and
it's wet on the 'engine side' of the carb body. I wonder that's actually
a sign of the problem, though, and it's just not atomizing the fuel
properly and is getting neat gas pouring into the cylinder rather than a
nice mist (the presence of just enough vapor might explain the way it
tries to cough into life once sometimes, then promptly dies).
OTOH, maybe I'm clutching at straws ;-)
Oh, other possible symptom: the carb's getting a *lot* of gas; it drips
quite a lot from the intake side if I have the air filter assembly off
(the bolt that holds the filter on runs right through the carb body on
the intake). It's possible it's always been like that, and that's normal
behavior, but it surprised me there'd be that much gas "upstream" of the
Possible, I suppose. I checked that the float isn't holed, and the
metering needle there looks good and seems to seat well (the carb sits
slightly lower than the tank, so if there were a float problem I think
I'd get gas pouring out everywhere even with the mower just sitting).
I can't completely rule that out, as there are a couple of passages I
can't really get to (access sealed at the factory), although I can blow
through them, so I know they're not completely blocked.
I might try to pull the flywheel (which times the ignition) just to check
that - it'd be a heck of a coinicidence if it just happened right at shut-
down last season, but stranger things have happened :-) I've certainly
had keys shear on smaller engines before.
Yeah, I just pulled it again and double-checked what I could. I ended up
dumping a little neat brake cleaner into the inlet "upstream" of the
float and throttle, and the engine actually turned about four revs under
its own power before dying (it'd only do about 1 or 2 revs by itself on
gas). I can't decide if that's indicative of anything meaningful or
On Fri, 30 Apr 2010 21:26:48 +0000 (UTC), Jules Richardson
If you do pull the flywheel, shine the magnets (two) with some emory
cloth. Clean any contacts and shine them.
I've seen surface rust (humid areas) on the flywheel magnets - enough
to diminish the good clean firing of the ignition.
Something I've noticed on engines like yours is the need for valve
clearance adjustment after the engine has rub for a number of years.
I've worked on a lot of standby generators and the overhead valve
engines are easy to adjust the valves on. The valve in head engines
such as the one I believe you have is a different story. I had one
that would only run if I preheated it with a propane torch which
caused the metal to expand enough to let the valves seal. Here is
a video that explains a lot about dong a valve job on a L head
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