lawnmower pullstart hard to pull and cant start

I cannot start my lawnmower due to the string being so hard to pull. The engine WILL turn as I pull the string but its just so hard to pull that there is no way that I will get enough force to start it. This happened just randomly last time I was using it. Everything was working just fine when I shut it down to empty the bag, but when I tried to restart it to continue this problem started.

To start off I do know the basics of an internal combustion engine. I have checked many of the common problems related to something like this but to no avail. Here is everything I have done:

Removed sparkplug and tried cranking it, but still stiff
Removed recoil and checked it. Pulls smoothly when not attached to engine
Removed blade
Removed carburetor and even cylinder head, then tried cranking but still stiff.

I admit that I am probably well overdue for an oil change on it but it did have oil when checking everything I just stated. Any suggestions on what else can be causing this problem?

 

Drain the oil out of it and look for metal filings in the oil. Use a magnet if you have one.

I suspect the rod bearing is frozen to the crank = likely a ruined engine.

 

Sounds like your engine brake is still on. Check the cable going from the handlebar to the engine brake and see if it is moving at the engine end.

 

my engine brake doesn't actually "brake" the engine. It only grounds out, or whatever it needs to do electrically to stop the engine.

 

Will try that today, but if this is suspect, why would it be running fine one minute and then when trying to restart after emptying the bag its "frozen"?

 

It would help to know what you have.