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