Small Engines (Lawn Mowers, etc.): Shindaiwa T25Iox pro model, tune ups, spark arrestor

Question
Aloha Eric,
Thank you in advance & sorry in advance for the LONG question! I'm on "All Experts" myself so I know how these questions can become TOO much sometimes. Anyway, I have a Shindaiwa T25Iox pro model (also says C4 on it). The unit RULED when I first got it but I live in Hawaii and work on a farm all day, so I use it quite a bit. The problem is: It BOGGS like nobodies business. I mean, it rotates SO slow, it's almost useless. Turn it in any direction & it almost stalls. Literally, it's like if you were on a riding mower and just kept playing with the throttle (up and down). It is so bad that the heavy grass that I cut gets stuck almost every swipe & I have to stop and unwind that crap. Frustrating to say the least.
So, do you think that I just need a tune up or have I fried the thing? Supposedly this was the TOP of the line when I bought it & was supposed to put up with HARD CORE usage (which admittedly, I do) but if it is just in need of a tune up, what does this entail? Are there any pitfalls that I want to look out for?
Bro,... I can not thank you enough in advance! You have no idea how much I need this thing. In Hawaii, it rains so much, you can hear the grass grow at night! haha
Anyway, respect man & if you like the band "sublime" I am your man. I'm on here as "GMan" (look me up) and I have EVERYTHING that they ever did, so I can hook you up if you'd like with some rare sublime stuff.
Peace,
GMan

Answer
Tune-ups cover replacing the spark plug, cleaning the air filter, cleaning the spark arrestor and rebuilding the carb if necessary.

I would start by makeing sure the air filter is clean.  Next, remove the muffler and locate the spark arrestor screen.  Clean the screen and muffler ports.  A wirebrush works well or you can scrape off the carbon deposits.  Replace the spark plug.  Put the muffler back on and see how it runs.

How old is the trimmer?  I worked on a lot of Shindawai trimmer in Aiea/Peral City at the Small Engine Clinic.  Some of the 94-97 model year T25 trimmer would were out the piston and ring pretty quick...I rebuilt a lot of them...so many I could do it in my sleep.

Anyhow, check the spark arrestor and replace the plug and let me know if it runs any better.

Eric