I have had my Echo SRM 2400 for almost 8 years now. I strip the thing
down every year [in January] to clean out debris and lubricate the drive
shaft. Several other things that I do to make weeding my 3+ acres a lot
easier...

First, when I load my .095" "string", I use 30' instead of the
manual-recommended 40'. It puts a lot less tension on the wound string
in the spool making the string a lot easier to come out, so very few jams.

Secondly, over 3 acres is a lot of weeding and my right index finger
gets very tired depressing the gas trigger hour-after-hour. So, I got an
8" piece of VELCRO [the self-adhesive kind] and glued it around the the
long drive shaft bar, just above the trigger. Another strip of 5" VELCRO
is glued back to back, with a small loop at the bottom, that just goes
around the trigger. When I start the whip, I fasten the "trigger loop"
around the VELCRO that I have glued to the drive shaft bar.

Just an easy pull on the VELCRO "trigger" until I attain the speed I
want, join the 2 faces of VELCRO together and I don't need to touch the
trigger again until I run outta gas... ;-)

Lastly, everyone has the same problem of the bottom "bumper" on the
spool eroding away from repetitious bumps to advance the line. I have
found a way to avoid buying a whole new spool, for a lot less than the
$25 it costs.

Go to Home Depot or Lowe's or your local hardware store where they sell
PVC pipe. Get a white, threaded, 1 1/2" PVC pipe cap. The next step
takes a little doing!

You've gotta thread that cap over the bumper. What I did was slowly file
all around that bumper to decrease its diameter, to conform to the
thread on the inside of the pipe cap. Not too loose, though! Once you're
close, if you have a wooden cabinetmaker's hand-screw clamp or a vise,
you can compress the cap to the spool bottom.

You have to be very careful about judging the diameters!! If you
compress the bumper too much, you'll bind the spool inside and prevent
the string from coming out!

However, once you have done this and got it right, you'll never have to
buy another string spool...until the little molded loop [on the inside
of the spool] breaks down! Mine is at least 3 years away from that
eventuality.

Let me know how well you make out and if I can help you more, I will.

All The Best!

Alan