Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Got a problem.  Pulled the trusty I think 43 year old Ariens snowblower (with it's second engine, a Tecumseh HSK70 with maybe 20 hours on it) out of it's covered outdoor storage space.  Wanted to look at the belt, grease it and lubricate what I knew earlier was a sticking shift bar (the shaft inside the case gets smeared every few years), so started it up to take it the the basement hatch.  It ran for a minute - just long enough to get there, then started running rough, then backfired through the muffler, and now I can't even start it.

Took apart the carb to check the flow and needle, found a clean fuel bowl but clayish colored fine particles in the gas.  Drained some through the inlet (float valve thing) and it was full of junk settling like an almost solid thin layer in the bottom of my container.  Then I'm thinking - didn't run it last year or drain it so the fuel was in there at least two years.   I can't remember the last time I filled the portable can so maybe the gas is three or maybe even four years old.  I probed the tiny hole in the needle adjuster and blew it dry.   And still couldn't start it, but it sputtered once. 

I hope this will help.
If you were to hold the carb just as it is in the photo.
Then take the bowl and put it on the carb as it's shown.
(and as I described in my last post)
Then lay the fibre washer on the bowl.
Then screw the bowl nut neddle assembly into the hole.
You would be done.
Nothing goes into, or between the copper tube that is in the carb body(called the Emulsion tube)
and the end of the Bowl nut main jet needle assembly that gets screwed onto the carb body.
To hold the float bowl on the carb.

If you have the carb upside down with the bowl on it.  You want the higher part of the
bowl to be on the opposite side from the float hinge.
Check out this link. It may be of some help as well.
Tecumseh Carb.

Be careful not to blow compressed air into the gas inlet tube.
(The pipe you slip the gas line onto).
If you do you can, and probably will blow the float needle seat right out of the carb body.
(been there done that)
Blow the air into the the tube that the needle jet slides into.
And have the air come out the gas inlet tube/pipe

Tecumseh carbs can be a pain.  I've had some off, and back on
three of four times.  Adjusting the needles a 1/2 a turn per
adjustment may be to much.  I usually do a quarter of a turn
in the beginning stages.  If the plug is coming out wet. Your getting to
much fuel for one reason or another.  With the choke on I would try just pushing the primer bulb once.
Using some Instant Start can sometimes help.  With the cylinder and plug dry.  Spray a little in the carb.
Don't prime it and leave the choke off.  See what happens.  With old engines you just don't know how much
fuel is too much.  The rings may be worn, valves may not be sealing as well as they should be.
So the compression may not be what it should be.  They will flood easily.
I would also put a new plug in it.  You just need to get it running so you can adjust the needles.
It can get confusing when talking about the float bowl and what is the
correct position.  Here are a few photos I pulled off the web.
If your holding the carb right side up.  The deeper side of the bowl
should be on the opposite  of the float hinge.  Or on the opposite side
of the fuel inlet tube.  That depression allows the float to drop
further down into the bowl.  The float hinge is on the fuel tube inlet
side of the carb.

Are you getting a good spark?
I would keep the throttle just a little above the idle position.
Start with the idle mixture screw at one turn out. The main jet screw (on the bottom) out 1 1/4 turns.
It should fire using Starting fluid.  At this point your just trying to keep from flooding the engine.
Your doing the right things.
Having the throttle set at max or 3/4 may have been causing you some problem.
Start from the beginning using a little starting fluid and see what happens.
I don't know for sure what the plug gap should be on that engine.
But .030 up to .032 is in the range.
Opening the gap up a little will give you a hotter spark if your ignition system is up to it.
You said that this is the second engine on this blower.  Was this a new engine?