Ryobi 139cc lawnmower advance/retard settings ?

You will have to re-do the timing.

Timings can be either advanced or retarded. Think of it like a clock. It’s normal setting is the 12 o clock mark. If you retard the timing it will be firing just before the 12 o clock mark. If you advance it, it will be just after.

So sounds like yours needs to be set back to the standard position

May be the transmission but they charge a small fortune for a new one. Go to lawnmower repair place and look for a junked unit with a good tranny. Replacement is not hard.

Instead suggest a mulching blade.
Check to see that the earthworm population in your lawn is healthy.
They will eat the clippings and create castings fertilizer for your lawn.
Most earthworms come out at midnight to feed.

There are so many different model for Ryobi cordless lawnmower, would you please tell which one you need?

All bearings today are factory sealed and are not greaseable, at least in this country. I really doubt Ryobi makes a greaseable bearing on anything they manufacture. Be blessed.

Here is the master thread for you:

http://www.thumpertalk.com/forum/showthread.php?t=673641

and some info to start:

Table of Indicator Readings to Advance Specs.

.027 5 degrees advanced
.022 4 degrees advanced
.018 3 degrees advanced
.014 2 degrees advanced
.010 1 degree advanced
.007 Stock Setting
.004 1 degree retarded
.002 2 degrees retarded
.001 3 degrees retarded
.000 5 degrees retarded (the limit of travel of my stator)
-.001 7 degrees retarded (the 3 to 5 and 5 to 7 jump are correct due to rod angle)
-.002 8 degrees retarded

Straight gas. Look around, and you will see where to fill the engine with regular sae 30 oil, and on lawnmowers, if you have a place to fill it with oil, you don't mix oil with the gas.

Remove the bowl from the carb. and blow it out with air.

80*cos40