Where do I buy (1) piston ring for a single ring piston for a Homelite Bandit SX135, UT20601C, S/N HR1560468, 25cc 2 cycle string trimmer in the Portland Oregon area?

Hi! smeds090, and welcome to AMHD :)

Here's a starting point:
Homelite :: Service & Support

Here's 75 locations from 5 to 76miles from Portland:
Homelite Locator

If the part is obsolete try Stens:
Stens Locator

Stens is strictly Dealer only, that's why you won't see their name, until you get the parts bag.
I did have Portland Org up, but it didn't save it. You'll have to type it in.

You could even search for part there.
Just type in all you know and it'll take you to a breakdown of all the parts available for your trimmer.

I just did, and all I could get for HLight was the trimmer heads

My supplier likes it, that I come prepared. Sometimes he will have a better option.

K

Hi,
I will answer in as much as I can. First it turns out that the SX135 had two engines, but you say it is the 25cc. That must mean the ring stuck. Very picky engine as far as fuel quality and mixture went. Used to use a "trick" to unstick rings in that engine.
At any rate you need a part #96935 and the dealer I could find with a good rating was Parkrose Mower. Family owned. Website is:
http://parkrosemower.com/products.htm
It is not listed as one of their main lines, but is listed. If you have a Sears parts and repair facility in the area (and I cannot imagine that you do not) then you could try them. They actually have more parts than most anyone; I can site examples of things that they alone have because of their purchase of certain business concerns.
Peace,
Clarke