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

I recently picked up a Airens ST1032 snowblower. It is in good shape but, when I bought it it was taken apart. The previous owner said it did not have any spark. I replaced the points and condenser and I also removed the cylinder head cover to check the condition of the piston and valves. They look good but i did notice a hair line crack in the cylinder head. (the part the spark plug screws into). It does not appear to go all the way through.

I am in the process of putting the motor back together, but with the cylinder cracked, I am also considering getting a new motor all together. How do i know if the head is trashed? It does seem to have a decent amount of compression, but it hard to tell, because i dont know what "normal" is for that motor?

It is a 10hp tecumseh HM100 motor

Any advice?

I don't think you have anything to worry about with that style engine. use it - if it leaks get a used head , unless it had been run low on oil engine should be good.

  The HM100 and HM80 used the same part number head and there are scads of junk HM80s around.  An ST with an HM100 at 32  is probably an 924xxx model with cast iron gearbox, differential, big tires and a super machine.  As a basket case you probalby got it for 50 bucks.  With rings and a valve lap that thing would be a tiger.

  I guess it would come down to how you feel about it but it could fail under load and cause some damage like a chunk getting into the chamber.  You are in there so swaping out the head now would eliminate a possible mid-season failure later.  It would not be so expensive and it's the end of the season so the added down time not a big deal.  

I am going to look into getting a replacement head for it. What do you mean be a cast iron gearbox? It does have the big tires, and the differential that can be changed for more traction.

The gear box came in three types in 924xxx's, two cast iron and one aluminum.  Many of the 1032's around are cast iron.  

     Those cracks may be just "Casting Marks"... if they were cracks, they would go (I think) all the way through with nothing to stop it.  Also if they were cracks comming off the plug hole,  The spark plug would expand them as it tightened up..

Remember what you said first... It has no spark... Put it back together and check your kill switch wiring and lockouts...

Good Luck,

Friiy

I got it back together tonight and it does have spark now. Replacing the points and condenser did the trick. Tomorrow morning I am going to see if i can get it running.

I can get a replacement head for $30, so I may get one anyway.

The cast iron gear box, is that in the front of the machine, up by the auger? If so, yes it is cast iron.

I have an Ariens 1032 as well. I go along with one of the other posters. What you are seeing on the combustion chamber side of the head could very well be a casting mark. It would be rather unusual to have a cracked head in my opinion. You would strip the treads out of the plug hole before over tightening a plug would ever crack the head. And if you've got good compression that would be another good sign in your favor. When you get it running you will know for sure. I believe that I have a used head off a Tecumseh 10hp. But I'll have to check to make sure. Keep us posted.

I got it running today, but it wont stay running. I soaked the carb for 2 days prior to today, got a carb rebuild kit, blew out all the carb with compressed air.  It will run on full choke, but when i turn the choke off, it stalls. I spent a few hours today adjusting the carb, but no luck.

I took the carb off of my st824 and (appears to be the same one) it started up and was running normal. So its definetly the carb. Any suggestions?

I was looking at new ones....

Pull the sick carb apart and clean it thoroughly.  Check your pilot and main jets for blockage.   Usually, the choke or enrichening circuit bypasses the normal fuel feed to dump higher concentrations of gasoline into the venturi to assist with quicker starting.  If the engine is running while choked but shuts down without it, your pilot and main jets are probably blocked.
Download an exploded view diagram for your carb to see how it comes apaprt.  Sometimes it's difficult to understand how the jets come out on some carbs. 

Where can I get the diagram that show hows the carb comes apart?

The motor is a hm100 159024D

  It's probably just some left over dregs and the carb will cleanup and be fine after another basic run through.  I dip in two solutions for 24 hours, give it an ultrasonic bath, then wash with carb spray then compressed air.  Occasionally it will act just like yours and it ends up some crud was missed.  I re-do the basics below and it's usually enough to get it going properly.   The chances of needing a new carb around about 200:1.

http://outdoorpowerinfo.com/repairs/tecumseh_carb_632334a.asp

 

Running a quart of gas through the tank out of the carb line to flush crud in the line that often causes problems.  Catch gas in a white cup and look for crud.  Often I'll run a half gallon through but still end up with bowl dregs after putting the carb back on.  The dregs are usually bits from the gas line that get loose from handling and break off later.

 

Spray through the carb inlet, both directions with the inlet line removed.

 

Check the carb seat is ribbed side in and fully seated.

 

Take the needle out of the bowl nut and spray in there.  Clean both holes in the nut with a thin wire, i.e. stripped tie wrap.  One is tiny and just above the bottom threads where the smooth area starts.

 

Run a thin wire up into the main tube i.e. runs from the bottom of carb into the throat.  Put slight bends in the tube so they just graze the tube inside.  Stick the carb spray tube at the tube and spray up into it.

 

Remove the choke butterfly and run a wire in the main jet air inlet at the base of the choke butterfly.  At least stick the carb spray tube there and spray in.

 

Check the float setting for 11/64 between rim and float with the carb turned upside down.  Use a drill of that size laid across the bowl rim. The float should just touch the drill.

 

Check if the needle is sticking on the seat by moving the float up and down a few time and watching the needle.  It may stick lightly but pull off as you lower the bowl.

 

Spray into the primer port and watch the flat on the outside of the carb just above the low idle adjust for a spray out of the air vent hole (tiny).  Also spray in the base welch cutout by the main jet base and watch for a fluid out of the same hole.

 

Remove the idle jet and spray in there.

Good Post Trouts.

-Friiy

I took the carb apart and soaked it again for 24 hours. I am going to blow out all the passages,, reasseble and give it try today. I will let you know how it goes.

Thank you for all the help so far.

I need to get a starter, and gas tank (I broke the tank when the pull start handle slipped out of my hand and smacked the side of the tank and put a nice hole in the it) The hole cold probably be fixed, but i am not sure what type of adheasive to use that will stand up to gasoline?

Does anyone have a good source for a starter and tank? Part numbers? 

 

made a little progress.....if I prime the carb it will start and run with the choke off, but only for a few seconds. Not sure what the next steps are? Possibly float adjustment? Vacuum leak?

One thing i noticed on the float bowl, it must have gotten a dent in it at some point, it was pushed back out, but not completely, could the float be getting caught up on the dent?

If the dent has increased the dimension of the float to cause it to get closer to the float bowl, it may very well be sticking in the closed position.   You  might want to move the float on it's axis to see how smoothly it moves with the float bowl off.  There is very little vertical movement but it should be smooth.  You might also want to make half of a simulated float bowl out of a tin can to use to see what kind of clearance the float has between it and the side of the simulated float bowl.  From what you're saying,  the engine seems to be experiencing fuel starvation.  Are you getting good consistent fuel flow to the carb?  You can test that by pulling the fuel line off at the carb and putting a container under it to allow the fuel to run  into it for a few seconds.  Take a good look at the fuel that comes out.  Look for water and dirt.    A picture of the float would be good to see.

You can get the Tecumseh factory number off the cowling and go to the link below for part numbers.  It should be stamped on top.

http://www.outdoordistributors.com/Tecumseh/Tecumsehpartslists.html

 

Do you have pullback causing the handle to pull out of your hands?  Timing.too advanced or gap too small causing an early fire?

 

Did you just break the starter cord with all the pulling?  A new cord can be strung pretty easily.

 

For the cost of a new tank and recoil you could get a motor.  There are plenty of glues around that will be ok with gas if the crack or hole is suitable for patching.  Patching a tank is a bother.  You can pickup a second hand tank

 

To see if it will run you can start it and keep punching the primer to get gas to it.  It seems like it still could have a block someplace.  The bowl is stepped.  The lower portion with the dimple goes away from the float hinge. 

I took the carb off of my other snowblower (st824) and swapped it, and it runs fine with no other adjustments. I went through the original one twice and have speant many hours playing with it, I think its time to get a new carb and be done with it. They seem to go for about $100.

The pull cord and recoil are ok, the handle slipped out of my hand once,and broke the tank.

dvdkea wrote:
Have you completely dis-assembled the carb down to it's basic components?  I.e. pulled and cleaned the jets, run wire and blown compressed air through the galleries, set float to spec, checked for manifold air leaks?  I've worked on a lot of carburetors for over 35 years and have never come across one yet that I couldn't fix.  Sure, might have taken a while to get it right but that was usually caused by being in too much of a hurry on the first or second go around.  

I did take the carb completly apart. Removed the jet, remover the chocke butterfly, and throttle butterfly, everything was apart, soaked it, and blew out all the passages, etc.

Something i did notice. The choke butterfly is bent. it appears to have been slightly beant so it would open and close. I did try to straighten it, got it flat, and the choke would not operate. Could the beant choke butterfly be causing this issue? 

If the engine is stalling because it's flooded, that could be attributed to the choke engaging after the engine is warmed up.  However, it it's a problem with fuel starvation, the choke will have no effect on that.  Next time you have it running and it stops, pull the spark plug to see if it's got any fuel on it.  If you don't see fuel, try to see if you can detect the smell of gasoline on it.  If you have evidence of gasoline, the engine is probably stalling from being flooded.  If not, you have fuel starvation.

I think it is starvation. I can keep it running with the choke off if i keep pushing on the primer. I have tried several adjustments on the main jet and also the air\fuel mixture with no real difference.

 

    If you can keep it running well for a while on primer then your gas line, float, needle are probably ok and no vacuum leak.  The float is working but the level could be off. 

    Your main jet needle should look like the one on that website i.e. the tip cut off.  7's and below had the pointed tip.  8's and above cut off.  You could try the nut and jet from the good working carb. 

    Some carbs are wicked fussy about the float level.  They are basically the same so I think it’s do to the way the machine sits.  Some ST824s sit level, some droop towards the handlebars and some a bit forward.  You seem starved so you could squeeze the float tab a hair to see if that helps.  If you can run for a short period (no prime) then it stops then let it sit for a while and it starts and runs for a short period again then it’s probably the float level.

    Are your carb linkages opening the throttle plate when you put it on full throttle?   You could open the choke butterfly and look in to be sure.

   1 turn on the idle and 1 ½ on the main jet are enough to get a carb to run so don’t bother with trying any adjustments until fine tuning after you locate whatever the problem is. 

 

   Seems like crud or a float adjustment. 

It is a new plastic float, the one that was originally in there was brass. The main needle jet does have the tip cut off, so it appears to be the correct one and is identical to the one that was in the carb before rebuild.

in this case, when adjusting the float level, i want to allow more fuel into the bowl, correct?

The carb linkages do open the throttle part way when the lever is at "fast" I was under the impression that this was normal, and the govenor would open the throttle more when needed. Is that correct?

I did install a inline fuel filter, could that be causing problems? but, then again, the carb from the st824 works fine with it.....

Trouts is probably on the right track.  I agree that it's probably a float setting issue.  I had a little two horse Evinrude engine that I couldn't get to run right for the longest time.  I was too lazy to pull the engine cowling off to take the carb out and tried to adjust the float with the carb on the engine.  Not a chance.  I had to take the engine apart and pull the carb to get the float setting right.  As he says, they can be very finicky.

The float and float needle work on the  principle of leverage.  When the float goes to the bottom of the bowl, causing demand for fuel, the float needle either opens on it's own with gravity or is pulled open via the float lever and a very small wire clip attached to the float needle and float lever.  The adjustment of the float is very critical and often only hav a millimeter or two float movement allowance.  If you have a fuel starvation issue, that means the float cannot move low enough and is not allowing sufficient movement of the float needle to permit sufficient fuel flow.  

I've had occasion when I couldn't dial in the float in and had to get creative.  So I carefully put the carb in a vice and rigged up a small bottle of water to the fuel hose going into the fuel inlet.  I then allowed water to flow down to the carb and controlled the float by hand to watch how much movement it needed to stop/allow the water flow.  This method is OK to get it close but water is heavier than gasoline and fine tuning might be necessary.  Focus on the float setting.  Sooner or later, you'll get it right.

    Never used a plastic float.  I don’t know if they ride different or are set the same way.  You can ballpark it by setting similar to the brass float then subtracting a hair from the tang to open slightly early.

 

>>The carb linkages do open the throttle part way when the lever is at "fast" I was under

>>the impression that this was normal, and the govenor would open the throttle more

>>when needed. Is that correct?

   Yes, the linkage throttle movement is a gross movement so it’s probably fine.  The governor is generally active at slowing down the motor (pushed internally by flyweights) or passivly being pulled back by throttle springs.

 

>>I did install a inline fuel filter, could that be causing problems? but, then again, the carb from the st824 works fine with it.....

 

   Also, draining fuel out of the nut will double check that  Remember, you just cleaned your carb and having problems which act like the carb is dirty.  You might want to check things again because it looks like some area you cleaned or set right is now dirty or set incorrectly.  It won’t need another dip but poking the passageways and verifying the float will probably cure it.

   Every time you put the gas line back on you are pushing hard on an old line that can easily break off crud immediatly or loosen the wall  which will fall off later.  Chances are the line did not come off easily and you had to use pliers or wedge a screw drive behind the line to get it off.  That puts a lot of stress on an old line. 

   

I think the emulsifier jet/ nozzle is slightly plugged and needs to be cleaned...

-Friiy

I give up. I adjusted the float several times with no difference in the way it runs. I ordered a new carb today.

dvdkea wrote:
See if Trouts wants your old carb  to find out if he can analyze the problem.  He might be able to press it into service on a machine he's repairing. 

I hate giving in to a misbehaving carb!

I hope you looked on Ebay before ordering in the new carb.  Big savings to be had there on stuff like that.

I may just throw it up on ebay to get rid of it. I'm sure it can be fixed, but i just dont have the patients anymore. They new ones are available on ebay for about $10 less than i can buy locally. I'll buy local.

I have learned a lot about the st1032 already. Seems like it will be a good machine. I live in upstate NY and we had a very mild winter, but I'm sure we will get a lot of snow one of therse years...

Any idea what a machine of that size\quality would go for today?

   It does get a bit messy and frustrating to keep making adjustments with no result.  You may want to keep your carb around for another crack at it later.  The new carb will not have an idle or main jet unless you snagged an old NOS carb. 

I was able to get a NOS carb locally that does have all of the adjustments like the original one does.

I am assuming these are better than the non adjustable ones?