Small Engines (Lawn Mowers, etc.): tecumseh engine

Question
Tecumseh 8 hp model#hmsk80 155692v engine surges up and down.mounted on snow blower.acts as if its getting too much air.removed carburetor cleaned and blew everything out put new needle and seat in.removed and cleaned jet on side of carburetor. ask advice from local lawn mower shop.reassembled and still surges up and down and wont idle. could carburetor be bad

Answer
Could be a bad carb.  You can purchase China made carbs on Ebay for less than $20.00.

I would check a couple of other items before ordering a carb.

First, make sure the intake gaskets are sealing as well as the manifold gaskets if you have manifold.  You can use some Permatex #2 non-hardening on the gaskets to make sure they are sealing.  You only need a little Permatex and use rubber gloves to apply a thin layer on both sided of the gaskets.  The #2 is some messy stuff and hard to remove.

Second, check the head bolt torque.  200 inch pounds.  I've seen some head bolts loosen and lean causing the engine to run lean.

Finally, before ordering a new carb, dis-assemble again and clean again.  I have had to clean carbs 2-3 times before they started working right.

Let me know if this helps.
Eric