get some Sea Foam. Did you clean the spark arrestor, If I were you, I'll take off the muffler, clean everything you can see. Change/wish the air filter and change the gas filter and spark plug first. Hopefully that will solve the problem. If not, it will start to point to the carb. I had problem with my one year old Honda HHT31 trimmer, idle but don't rev. End up new carb.

Check the tubing for blocking or cracking since it is a few years old and loosen the gas cap help. run two tankful with Sea Foam to see whether it can clean any of the blockage out.

Good luck, write back after you try it and we'll talk more. Did you ever adjust valves yet? Don't think that is the cause though.

Took carb apart. Light thru main jet was odd shape and fuzzy looking. Gently cleaned main (only?) jet. Light shows clean round hole now. Runs great, lots of power.
New problem. Removing carb caused fuel filter line to disconnect inside tank. Is there a special tool to reconnect? maybe something like a extra long needle nose pliers? Thanks,
coho

You mean fuel filter or the line. For filter, bend the coat hanger and fish it out. Line? you are on your own!!! All my stuffs are tubing directly through the rubber gromet, no connection what so ever, filter is on the other end inside the tank.
I'll look at mine too. I got my old carb back and my trimmer still not running quite, I might do it your way.

Now is my turn to ask you question: can you explain what you do a little bit more so I can try it myself. Mind for sure is some blocking on the jets already.

yungman, first, thanks for the sea foam tip. I read about it a long time ago and had forgotten the name. Next time I will set it up so can primer carb full of seafoam and let set for maybe a week then flush and run with fuel with some SF in it.
Honda has line connectors inside tank and outside tank. They are pushed thru rubber gromet and line inside tank came off. If no one has a solution, I will make up something to hold tube near end, lightly lube and try to push it on. Always like to see if there is a better way first.
Take carb off of engine and carefully take it apart. take care on gasket removal or you will be buying new ones. I like to take apart in a shallow box or pan to catch any loose parts. a paper towel will prevent parts bouncing out of pan. Carefully inspect all parts and especially jets for clean ports and holes. A very fine wire may be helpful. Only remove build up and dirt/crud. Do not en-large jets as non adjustable carbs are made just the right size (at least some are) This was my first time on a non adjustable carb. Next is a 20 year old line trimmer. This one runs good if you can get it started. Not sure what I will find. Luck
coho

Thanks for you info, I am going to try this for sure over the holidays.

BTW, can you remove the rubber gromet and rehook it back? I am flying blind because I have not seen something like this. Both my Hondas is not like that, tube just go through the gromet. Apparently those are standard stuff, I brought my trimmer back thinking was a warrante service, end up charging me!!! Should have done it myself. Long story short, we had a shouting match, I paid half and got back all my parts.....that I found out that they replace the rubber gromet also and I have that with me. So maybe go buy one with tube through if your tubing has hardened.

Gromet was installed from inside the tank. Sure could pry it out, Not sure could put it back in. Rather not try. Sure it will be easier to reconnect what I have now.

The simple solution was to take a piece of 3/8 od tubeing, put a small bend in one end to better align with the fuel barb in the tank. Blew a loop of string thru the tubeing and noosed the fuel tube near the open end. Dropped the filter and rest of tube into tank and pushed noosed end onto fuel barb. loosened noose and removed from fuel line.
Runs good as new.

Good for you.

Now I have to find time to do my carb!!