My Honda HS 520 Snowblower quit yesterday evening with flame bursting from the exhaust pipe. It had been working well. I tried to restart it a couple of minutes later. It started very weak and lasted for only a couple of seconds. I tried to start it again several times this morning without any luck. The engine didn't even respond. The spark plug appears to be OK but wet (maybe I tried many times and engine was flooded). The snowblower is relatively new (bought in 2006). Can anyone give me any advice what I should do next?
Thanks.

Could be flooded... but I'm going to take a guess that you may blown a piston ring.

Take the spark plug out... take a finger or thumb and press it over the spark plug hole. Pull the starter cord slowly. On the compression stroke you should feel the pressure build under your finger. If you don't really feel this... then you have a compression leak..
So maybe the rings... maybe the exhaust valve...

Four-stroke engine - Wikipedia, the free encyclopedia

Hi.
Your "weak" part of your statement says that there may be a great deal of friction. Does sound flooded, but check lubrication(oil) first and then try to clear engine of excess fuel.
Peace,
Clarke

Thanks. Jack and Clarke.

I followed your suggestions to check the blower but found nothing wrong. I then called a Honda dealer. He suggested me changing the spark plug and it worked. Thanks for your help.

Steven