Both normal. The Duraforce has roller bearings on the rod journal. These bearings must be set up with some play. You are hearing the slight knock on starting and coast-down. The engine also has reed valve slap that sounds like valve train noise in a 4-cycle.
Obviously there is no oil in the crankcase like in a 4-cycle. The oil is in the fuel. When the piston goes up, air/fuel/oil is drawn into the crankcase. When the piston comes down, this charge is compressed until the piston clears the intake port in the cylinder which allows it to be pushed into the combustion chamber. The seals on the crankshaft have to withstand vacuum and pressure. Some air/fuel/oil is expected to be pushed into the main bearings to clean and lubricate them, and some of the oil residue will be seen on the crankshaft. It's not a problem until the lack of containment of the air charge affects engine performance. It's not unusual to have to replace these seals sometime during the life of the engine.

ahh ok thanks that makes sense..thanks for the knowledge! I went down and moved the blade slightly back and forth about an inch and certainly there is that clank sound! So that's normal play then? Blade, shaft feel tight tight to me.

I've slowly been replacing a few things on it since I got a deal on a cub cadet 4 stroke ...but it's heavier than heck, smaller deck, doesn't mow as well or have as much power as the lawnboy so was going to sell the cub to a neighbor but was assessing the condition of my old LB.

Do the mufflers wear out on these things? no holes or looseness I'm just wondering about internal baffle,etc if replacing it would quiet it down some.

Switched to echo 50:1 that i run in my trimmer (since that's all i had since i haven't ran this one in awhile), seems to run much better on this stuff..could it damage it?...i've read these partial synthetics you can run at that mix in them.

Respectfully disagree with you Sax on this one. The sound he is hearing is piston slap. It is common among 2-cycle engines in general but even more so with the Duraforce. I suspect the Duraforce has slightly more piston to cylinder clearance to begin with than older models. Anyway, as the crankshaft is partially either up or down it the rod puts a lateral force on the piston and causes it to "slap" against the cylinder wall and make a clanking sound. The sound is more prominent when the engine is slowing down or speeding up. Water cooled 2 cycle engines dampened the noise quite a bit because of the water jacketed cylinder as opposed to the noise amplifying fins on air cooled engines. Suzuki and some others went so far as to put rubber cushions between the cylinder fins to dampen the clanking sound. The sound he is hearing could be worse than normal if the engine has ever had a partial piston seizure. Now.....that being said, It is slighly possible that a crack in the rod on the big end with excessive play in the needle bearings would make a clanking sound but it would not be long for this world if you know what I mean.
Piston slap is the noise that gave 2 cycle Japanese motorcycles their characteristic sewing "machine" sound. One of the worst offenders in the piston slap noise arena was the Kawasaki 750cc triple. It was an air cooled wildly ported 3 cylinder big bore 2 stroke that would throw you off in a heart beat. It had a ton of piston slap because they has to make it relatively loose to prevent seizures. The Suzuki 3 cylinder 2 cycle 750 was water cooled and much quieter.
As far as curing the noise in the Duraforce. If it is bothering you too much about all you could do is replace the piston and hope you have a tight enough piston to cylinder clearance to not make the noise. A completely different engine of a new shortblock would solve the problem too.

'One of the worst offenders in the piston slap noise arena was the Kawasaki 750cc triple.'

It also is a legendary street bike. I remember seeing and hearing them in 1969 (I think) in Indianapolis. What a sound! 3-cyl in-line 2-cycle, transverse mounted. They were said to out-drag any street-legal car, and you know there were some incredible cars on the street then! What a rocket.

swade12; you can run the 50:1 oils but never dilute Lawn-Boy or any other 32:1 oil to a higher ratio. A good 2-cycle trick is to add 1 oz/gal of Marvel Mystery oil to your mix in addition to the regular oil. All engines love this stuff and 2-cycles particulary will run cleaner and presumably last longer with it. It has been used for generations as a gas and oil treatment. One guy posted a few years back that he ran his Lawn-Boy out of gas and put some MMO in the tank to pull it through for a wintertime 'fogging oil' - was he ever surprised when the LB started on it! Obviously it only sputtered and smoked, but he certainly accomplished the fogging! I bet there wasn't a mosquito within a mile!