Echo SRM 260 String trimmer idle only

Hi. New to your forum, and need some direction. I have an Echo SRM 260 weed eater. I let it sit for about 10 weeks this summer with gas / oil mix in it. Went out to fire it up today, and it starts, but will not accelerate. With the choke full on, i can hold throttle wide open, and it does not rise in RPM. If I switch choke to off, weed eater will idle for a bit and die. If I attempt to increase the throttle with the choke off, it dies right out. I dumped out the old fuel mixture and went and bought fresh gas / oil mix. No change. Removed air cleaner and sprayed carb cleaner into air intake. No change. Removed carb, sprayed everything I could image with carb cleaner. Put it back on, no change. Did it all over again. Removed muffler, attempted to start, same behavior. Will start and idle, will not accelerate. Put it back together and joined your forum. Any ideas?

And I thank you in advance for any guidance.

 

First welcome to the forum,
It sounds like you have an air leak so depending on the age of the trimmer it is usually the fuel lines that are first to go bad. Then with the trimmer running and you are holding the throttle open, spray carb or brake parts cleaner along all of the mating surfaces behind the carb and along the crankcase, if the engine tempo changes you have found the leak and can take the appropriate action. Give it a try and post back with your results. Have a good one. Geo

 

Thanks for the response. OK, I removed the fuel lines from the tank. Blocking one end on each tube, I blew into them. I could not detect any escaping air. I reversed the draw [sucked on tube] till they collapsed. Filter seemed to flow both ways OK. Put tubes back into tank and reconnected to carb. Started, and as you suggested, sprayed brake cleaner around carb / intake. The engine rpm tempo DID indeed change. After several attempts to locate the leak, I gave up. Where would suggest I go from here? Carb kit? If so, who would I contact on line? I have no idea of the make of carburetor or model #, if that is the route I need to go. I live in the Boonies, and the quickest most affordable means of getting parts is on line.
Thanks again for your response, and I will wait for more input!

 

Carb kit is not going to help if you have an air leak, do not spray the cleaner into the intake you must spray it along mating surfaces(where parts come together),gaskets, etc. Tighten all the crankcase fasteners you can find and look for the leak again. You really have 2 choices, find the leak, if it has one, and fix it or trash the item, sorry. However it may not have a leak and other options are available. Have a good one. Geo

 

OK, I will try it some more. It is a bit of hand full to hold the machine, keep it running, spray cleaner, adjust choke, feather throttle, restart, repeat, and know where the leak is! There was not any one place that I could spray and get a response. It seemed that when the carb area was drenched, it would "take off". I will attempt to rig something up to hold the weedeater in place while I spray it again. Do you think the leak may be somewhere other than in the fuel intake area [carb]?

 

Yes, the leak can be anywhere two pieces of the crankcase or crankcase and seals come together or a cracked fuel line, if you haven't cleaned the engine look for an area that has an oily buildup. As the piston travels down it creates pressure in the crankcase and forces fuel into the combustion, if there is a leak it looses pressure out the leak and doesn't force as much fuel mix into the combustion chamber, as the piston travels up it creates a vacuum in the crankcase to suck in more fuel, if there is a leak, rather than sucking in fuel from the carb it sucks air through the leak which leans the fuel mix causing you to apply the choke to get enough fuel for the amount of air being introduced. The engine changing tempo is an indication of a leak, however if the engine picked up fumes from the spray through the intake it would also change tempo since that is like priming the carb. Have a good one. Geo

 

OK. Duct taped weed eater to deck rail, taped trigger wide open. Now I was able to methodically go gasket by gasket. On this machine, in succession, there is the carburetor, a gasket, an insulator, etc. to the intake port. At the gasket between the carburetor and insulator, I got it to stall out three times.
I moved on to other areas where gaskets are located on the carburetor and around the crankcase. This gasket at the carb / insulator union was the only place that I got a reaction from. I had it a part twice, and the gasket was intact, however, it appeared to be thinner at the top. So. New gasket?

 

Try replacing the gasket and check the insulstor for cracks. While you have the carb off, might as well disassemble and spray all the holes, cracks and crevases with brake parts cleaner. Have a good one.

 

I replaced the gasket between the insulator and the carburetor. No change. So.
I took the carb apart for the fourth or fifth time, cleaning everything in sight with aerosol cans of choke and carburetor cleaner. I stuck the straw everywhere. Opening and closing....This was the first time I opened the throttle mechanism as I cleaned ports and flushed every hole and crevice. I had already taken that part off in the previous cleanings.... I put it all back together and....I have a good running string trimmer again. Wish I could pin point what I cleaned that brought about the change.

Thank you for the input and moral support.

 

Glad to hear you got it going, sometimes those little carbs can drive you crazy, I really don't enjoy working on them because they are so touchy. Have a good one. Geo