I got my push mower out for the season and did the regular tune up - It was running great for the first mow. I checked the oil and subsequently ended putting too much oil in the mower and tried to start it for the second mow - I can not get it started - I have drained the excess oil, cleaned out the carburator - which contained no oil, removed the air filter, removed and cleaned the head and spark plug - including starter fluid into the spark plug area. I am not a whiz with lawnmowers but I can do some things.
When I pull the string it acts like it wants to start - shoots smoke out of the air intake and does nothing - then after a couple of pulls the string gets hard to pull and locks up a little-

New gas, new oil, cleaned carburator, cleaned head, I am going to buy a new plug today but I am not hopeful that is it.

It is a Craftsman 6.5 Horsepower Mulcher self propeled mower

Anyone please

Ok, when you had the head off, all worked basically right? Usually when too much oil is used, they spit it back up, or can break the rings... About all I can think it may be, is a sheared flywheel key.. you'll have to take the flywheel off and check. You say 6.5 hp, but what brand? Is it a over head valve or side valve? As for the oil, about how much of too much were we dealing with here? A whole quart?

Yes it was probably about a whole quart - it is a briggs and straton engine -Craftsman - I don't know about overhead valve of side- I think I am going to buy a new one- I have messed with a lot

Really ain't no need to get a new one right now... I would check the flywheel key, the next thing would be compression... the basic things it needs is spark, fuel and compression... by the way, a side valve would have the valves beside the piston, over head valve over the head. Ohv's usually have a cover saying ohv.

OK it is a side valve they were next to the piston - I cleaned all of that, it has fuel, it has spark, and I am not sure how to check compression. I am not sure about the flywheel either. I guess I will do some research on the internet but I do not have the manual or any first hand knowledge on lawnmover flywheels -- would that have been affected by too much oil?

Really don't know until you look, to take the flywheel off you'll have to take the shroud off, and the nut down in the bowl there, and pop the flywheel off (rubber mallet hitting it all the way around works) and check the condition of the key... (flywheel nut torque settings can be gotten from the briggs website) to check compression you'll have to have a compression tester, over 80psi is all right. Its just a sequence of ruling out things...

I put much oil in my lawm mower , now it wnt start

Where are you on this issue brian?