A WORD ABOUT 2 CYCLE HAND HELDS

[Deere2me]

" My trimmer won't rev or has no power... I checked the muffler screen and it looks OK " Ya hear that a lot on here and elsewhere,no?
Well, here's what Ive found over the last couple years: Most all the two cycle handhelds nowadays have a catalyst honeycomb in the muffler. Which is why they're so heavy. The cat. is there to clean up the exh. emissions, just like on yer car. I'm not sure if the cat is treated with metals or chemicals, but it's a big mass that tends/needs to stay very hot to do it's job, which means the exiting gasses are way hot! So the exh. screen tends to stay cleaner longer! Meanwhile the cat creates just enough back pressure to allow the exh, port to get clogged over a shorter period of time.
What all this babble means is, just 'cause the screen is clean, ya still need to check the exh. port! And clean it! ( read BLES' post about his Echo...)
Now Stihl 2 cycle seems to be the exception. Their screens tend to clog up, especially the screw in type. Cause most of em don't use cat. mufflers.
While you have the muffler off, check the condition of the rings and cylinder! I use a pointy object such as my knife ( hey, my shrink said I could carry it! ) to push aginst the ring/s. If they don't spring back a bit, they could be stuck, and no matter what ya do, it just wont run right!
As I mentioned before, pulling the muffler to check the port and cyl. is the first thing I usually do onna 2 cycle handheld! Or anything 2 cycle for that matter.

Other things that can contribute to port clogging:
1. Running the trimmer/ tool at less than full throttle for extended periods. ( Most homeowners are guilty of this)
2. Running the trim. with too long of string. With no shield, ya lose the line cutter! ( see # 1)
3. Running too rich an oil mix. " I think I'll add a little extra oil just to be safe" WRONG! With today's oils yer just wasting oil and creating headaches fer yerself!

Obviously, the carb & fuel system can screw things up too. But that's another story...

[motorhead64]

All good points, and also, don't forget, if it's a Toybilt...oh, I meant Troybilt...make sure you say nice things to it, wash it with a warm cloth, and anything else that makes it feel good about itself, or it may refuse to start or run like crap. MH

[okie]

That's a pretty nice write-up............even if it came from a grouchy old man.

One of my trimmers is down for the moment. I am going to follow your advise and see how it goes. If I get it running ( or not), I will let you know.

Travis

[bgsengine]

All good points, and also, don't forget, if it's a Toybilt...oh, I meant Troybilt...make sure you say nice things to it, wash it with a warm cloth, and anything else that makes it feel good about itself, or it may refuse to start or run like crap. MH

Troy-Bilt.. MTD.. Cub Cadet.. Yard Man..Bolens.. Ryobi (some) .. Craftsman (some).. all the same animal

Same can be said for Husqvarna (Poulan Weedeater Craftsman,Jonsered,Snapper) As can be Homelite (Ryobi, Toro (some))

[KE4AVB]

Yep, all 2 cycles are temperamental at times like relatives. The newer ones are even more troublesome. Rings are sticking, cylinders going bad, carburetors that refuse to be repaired, starter cups stripping out. It all come down to poor designs using the cheapest part in an attempt to meet the public demand for low priced products.

I have worked on 30+ years old saws and trimmers that run better half working than the new cheap stuff straight out the box. Most these customers buy these cheap things, gripe about their performance, yet they just keep buying the same thing again and again. The worst thing about they act like us techs are at the fault for the repair costs being so high.

[Deere2me]

Well bunky..... here's how I do it:
Pull the plug if ya haven't already.
Move the piston to BDC.
I use my blowgun inserted in the plug hole to keep a steady flow of air blowing the carbon/crud outta the port.
If no air, then try to keep the port straight down and let gravity do its thang.
I use a narrow knife blade to scrape the carbon out while keeping the air goin'.
You wanna use a dragging /scraping motion from the center out. In other words, don't push in, always drag out! The reason is you don't wanna snag the cyl. chrome plating at the port/cyl. bore edge. ( not likely, but ...)
I usually finish with a small round file, always pulling out.
If ya don't feel comfortable using sharp pointy thingies, then use a popsickle stick or a piece of hard plastic.
Finish by using my blowgun with the long skinny nozzle in the plug hloe and kinda workin around the edge of the piston as you move it up and down to dislodge any stray carbon bits.
Without air, I suppose you could flush out using copious amounts of mix gas, but I've not tried that.

Some people turn the port up and with the piston covering the port use carb dip or another chemical to soften /remove the crud, but I ain't never got time for that.

[thomd51]

a way to check if the rings are free, after takeing the muffler off, squirt a little fuel on the side of the piston and rings, then move the flywheel a little each way and the fuel will bubble a little as the rings move within the ring lands. TOM.

[Deere2me]

a way to check if the rings are free, after takeing the muffler off, squirt a little fuel on the side of the piston and rings, then move the flywheel a little each way and the fuel will bubble a little as the rings move within the ring lands. TOM.

Good tip!

[Mek-a-nik]

I found this to be true with my own Echo trimmer. The exhaust port size is apparently very critical. Mine wasn't too bad, but it runs very well now.