Bought a new snow thrower last year, and have had this problem since day
The engine is a Tecumseh HMSK 80-110 on a Troy Bilt Storm snow thrower. It
starts just fine, but pops out of the exhaust as it's running. Then at
times, it will run very rough, with the idle going up and down, then stall.
I find that if I play with the choke, I can usually keep it from stalling.
So, it looks like some kind of gas flow problem or maybe a timing problem. I
plan on replacing the spark plug, but have no clue if there are any
adjustments I can make on the carb (or how to get the cover off! This is a
Troy Bilt Thrower).
If responding to me directly, please take out "REMOVE" from my e-mail
Any chance you didn't summerize it properly and there's a little water
in the fuel tank which occassionally finds its way into the carb?
You might try adding a small amount of gas tank "de-icer" to the fuel
and see if that helps.
Was it brand new, as is in you brought it home, got it out of the box, and
put it together or was it lying around the store or maybe outside in front
of the store? If it was laying around the store there is a good chance that
it had been at least cranked up before you bought it...may have some
crystalization in the carb which has freezed up the float. I am not sure
your carb has a float or not, but I am willing to bet it does. See if you
can't get into the carb and see if it is clean or not. I had the same kind
of problem on one of my mowers last year and more recently on my power
washer. Both had Tecumseh carbs and they needed to be cleaned out. The
power washer was only a year old and had sat awhile and the float was stuck.
One thing I totally forgot to mention. I recall this happening last year.
When priming the carb, I found that sometimes some gas would come out from
the carb area. I know this probably means there's an air leak or something.
Sorry for not mentioning it sooner before replies, but it happened last year
and just slipped my mind. I have to take the cover off the engine (the cover
that Troy Bilt puts on) and see if I can see where the gas is coming from.
I'll report back on this.
Thanks again for all the replies.
Update: I got the cover off and started it up. It runs fine at first, but
had to play with the choke to keep it going. It will run ok after it's kept
going with the right choke setting, except for some popping out of the
exaust. I noticed a few things:
o In a previous post, I mentioned that gas comes out of the carb area when
using the primer. I find that the gas comes out of the air intake (correct
term??) after about 5 pushes. This may be normal, but I don't see it
mentioned in the manual.
o One time, the engine, just sitting there idling, the idle would start to
increase and decrease, and then the engine stalls. If I prime the carb
again, it starts again on the first pull. While it was stalling I quickly
adjusted the choke to see if it would make a difference. No difference at
all. Almost as if the carb was not getting any air (not the case) or the
carb wasn't getting any gas. Just like I turned off the key.
o I notice that if I run the engine at full throttle, it runs a lot rougher
(pops out of the exhaust) than if I were to run it something a little slower
than full. With the right choke adj at a slower RPM, the engine seems to run
ok (less popping). So, this may be my fix for now, but shouldn't be this
o According the Tecumseh owner's manual, there's a bowl drain at the bottom
of the bowl. I notice this collects small amounts of gas as it's running.
Could it be leaking air into the carb?
Let me ask this. To clean the bowl, do I just need to remove the nut at the
bottom of the bowl to remove it? I'd also like to try to set the carb
settings to, I believe, 1 1/2 turns, but I have no clue where the screws
are. I see one that looks like it has a grey cap on it.
Took the bowl off, cleaned out some residue. Looked like tiny yellow globs.
Replaced the plug from Champion RJ19LM to a Champion 5861 which is their EZ
start plug. I thought that since the engine was missing, it might be the
plug. Started up, and seemed to run a little better. The real test will be
out in the snow for extended useage. I think that as long as it doesn't give
me too much trouble, I'll get through the winter with it running it at a
slightly slower RPM. From what I've read, that may be a sign of a mixture
problem. Still, the blower is operational with it. It's a matter of, will it
stay working, or stall out on me on extended use.
If anyone has any other suggestions from the information I've given, let me
Have you tried adjusting the mixture screw that is at the bottom of the bowl
under the carburetor? I had similar symptoms as you--rough running, needed
choke to keep it going, poor low speed running (stalling). Turn the screw
all the way in--don't tighten it too hard against the seat. Back it out
about 1 1/2 turns. Make small adjustments from that setting until there is
a good balance between the high speed and low speeds.
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