Chainsaw Repair

Just helping on the 3516 right now.  Poulan pro sales directly and has manuals for both.  http://www.poulanpro.com/products/chain-saws/

Order parts right here    http://www.ordertree.com/poulan/

PWE
530057907
CLUTCH ASSEMBLY
5.45

Thanks for the link, cut4fun.

3000fps, I'll look into the safety chain issue. I didn't know there was such a thing. I do sharpen my chains myself. One problem I did have with the smaller saw was that after sharpening it for awhile the saw started cutting in a curve rather than straight. It may have been the bar, I don't know. Someone told me to flip the bar, but I didn't have a chance to try that yet.

Farmboy is correct it probably is the chain.  If you get it sharper or if the teeth are longer on one side more than the other it will make it cut in a curve.

Make a pass at sharpening the the cutters on the side that doesn't cut good.

forginhill
I would suggest that you either get someone, who truly know how to sharpen chain correctly, to show you proper technique and then critique your sharpening method; or pay someone to sharpen your chains correctly. You are going to need a number of sharp chains to cut your load of mesquite, as it appears to contain many roots which will be covered with fine dirt and the bark will be embedded with dirt carried by the wind.
I would also suggest that you continue to use the safety chain - the difference between safety chain and chain with no protection is not that great for the average user. There is no comparison between safety with the two types of chain. It is virtually impossible to be killed or even serious hurt with safety chain; while there is a  good chance that non-safety chain can seriously damage or even kill an inexperienced / average user from kickback. If you had ever seen the photos of cutters serious injured or killed by kickback (including people with their head cut off); then you would not even consider using non-safety chain. Is a couple of seconds worth your life?
Your 3516 bar is covered in a very fine sawdust which indicates that your chain is very dull. If it was sharpened correctly and the depth gauges set; your cutting performance would improve dramatically and it would not cut in a curve. I imagine that you will find that it will cut a lot closer to your 5020, as there is only 8cc difference between their engines.
I really doubt that you need a new clutch on your 3516, clutches don't normally lock when they wear unless spring for shoes is broken, or you were cutting in very abrasive material (very fine dirt) which is just grinding your clutch components away. The clutch was probably just locked from long threadlike fibers from the palm tree that you cut. These can lock a clutch up so it can not turn, plus fill the gaps between your cylinder fins causing saw to overheat  - this may also be part of the reason for poor performance as the engine may have scuffed from overheating. I would suggest that after cutting palm trees, that you always clean your cylinder fin gaps, under starter cover and under clutch cover.
Why don't you post a photo of your clutch drum and also your clutch driver & shoes before you spend money for parts that may not be necessary.