Small Engines (Lawn Mowers, etc.): Techumseh 7 hp snowblower wont start, engine replacements, cyl head

Question
QUESTION: Ben,  My 7hp Techumseh powered Toro 724 snowblower wont start.  The engine spins so freely that it seems like there is no compression.  I took out the spark plug and put my finger over the hole and hit the starter button.  It feels like it has compression but it doesn't really blow my finger off of the hole.  I feel the force of air trying to escape but I can certainly stop it with my finger.  Also, I can't feel anything trying to escape from the exhaust port when I crank the engine.  it definitely sounds as though something when wrong internally.  Do you know that most common problem is so I know where to start?

ANSWER: Kurt
Sounds like the rings are the problem letting air & oil pass by the piston. See If you can get a compression test done on the engine. Most shops will do it for free, then you will know what is wrong and how much it will cost and if it worth the money to repair it.sometimes if the equipment is in good shape you may be better off replacing the engine. There are a lot of deals out there for engine replacements.

---------- FOLLOW-UP ----------

QUESTION: Ben.  Thanks for your response.  I tore into it this evening.  I removed the cyl head and found that the valves were not moving when I spun the engine by hand.  They were both dropped which explains why I have some compression.  My curiosity got the best of me so I tore the engine down to reveal the problem.  The camshaft actually broke right where the shaft meets the gear.  The shaft itself was just sitting there in the bottom of the crankcase.  Any idea what would have caused this?  Is it worth repairing or should I just go the route of replacing the entire engine.

Answer
Kurt

A broken camshaft is usually caused by a connecting rod or other rotating part coming loose and striking it. Sometimes the cam will break after a short time of use because of a crack or fracture in the cam due to rough handling during shipping or improper handling prior to installation. As far as rebuilding the engine see if there is any more damage to the heads or the block and how old is this engine? You can buy a new Tecumseh snow king  engine for around $200.00