Can anyone fix my string trimmer?

[HappyGoLucky]

Hi there! I have a Ryobi 2800R string trimmer and it won't start. If someone is familiar with small engine repair and can get it going again, that'd be great!

It seems my original $20 offer was too low for someone to fix -- no offence intended. I thought some people get a kick out of the challenge, but maybe not. But honestly, I'm just trying to get this POS fixed without spending much. Doing the work is no problem, and I'm hoping to learn a lot through these exercises.

Thanks in advance for the help!

[sunnybono]

When you say its not working, what is actually happening. When you pull the cord, do you get a puff of smoke from the exhaust??? 2 things to check.

1. Oil:gas mix. if its too oil rich, it will be harder to start. Therefore, I usually add a little extra gas into the tank directly, prime it, then start.

2. Spark Plug. See if it needs to be replaced???

sk

[HappyGoLucky]

When you say its not working, what is actually happening. When you pull the cord, do you get a puff of smoke from the exhaust??? 2 things to check.

1. Oil:gas mix. if its too oil rich, it will be harder to start. Therefore, I usually add a little extra gas into the tank directly, prime it, then start.

2. Spark Plug. See if it needs to be replaced???

sk

I pull on the rope, and it pulls fairly freely. No smoke, no sounds. Fresh mixture of oil and gas, as well as new sparkplug.

[virgoan]

There's $20 in it for anyone who can fix it!


No offense...but $20!?!? that's more like an insult...I suggest u remove that...I know the trimmer doesn't worth much and it doesn't make sense to spend more than $20 to fix it...but for $20? why not just offer them a 6-pack? it sounds much better...

[Bazooka Joe]

No offense...but $20!?!? that's more like an insult...I suggest u remove that...I know the trimmer doesn't worth much and it doesn't make sense to spend more than $20 to fix it...but for $20? why not just offer them a 6-pack? it sounds much better...

+1

As for the trimmer itself, are you saying there's no compression whatsoever? Is that what "no noise" means? If so, that's very likely a serious problem that will not make sense to fix.

If you're getting compression and this thing is on it's last legs, here's a little trick. This isn't good for the engine, but will bring one back from the dead for a few seasons.

Pull out the spark plug and spray a quick (half second or less) blast of "carb cleaner" in the hole where the plug came from. Give it 10-20 seconds to air out a bit, then put the plug back in.

If you're getting compression, you can also rebuild the carb which isn't as big a job as it sounds. You can get a rebuild kit online for about $20, and even if it's your first one as long as you're mechanically inclined you can do it in a casual hour.

You could also check the spark by grounding the plug to something and pulling the cord.

Other information that can help us help you is:

When did it last run? Did anything happen the final time it was running? Did it smoke, need to be choked to run, have trouble at high RPMs?

When you put the new gas in, did you drain the lines?

[HappyGoLucky]

Thanks for the replies! I've updated my initial post and put on my flame retardant suit! :D

Anyhow, let's try and figure this thing out. I'm mechanically and technically inclined, but I have little experience with small engine repair.

So, here we go:

1. How can I tell if I have no compression, short of doing a real compression test? I thought pulling on the cord in a certain manner/frequency/... can help determine this??

2. Techinically, how would the shot of carb cleaner help?

3. Checking the spark was something I wanted to do. Any telltale signs I have no spark?

I had another post regarding this same machine here, when it was "working" -- but essentially, it ran for a couple mins, or more like 30 seconds or so, and then stopped. Opening the throttle was the only way I could get it to go a little bit more. Seemed like when it had load, it cut out for sure. But maybe this is a clue: I noticed that if I tilted the machine back, that is, make the shaft almost parallel to the ground while I increased the throttle, that helped a lot. If I kept it down (as if normally cutting), and then increased the throttle, it would likely still cut out.

Oh, as for smoking, umm, not so much now. It used to a bit, as well as leave some real oily residue at the back, but I reduced the oil ratio and that seemed to stop. I doubt it's running too lean or rich now.

As for choking, good question: When it cut out, I always had to put it into "A" (full choke I guess), start, then move into "B". It wouldn't run long enough to move it into "C". It would never restart in position "B", even if warm.

And nope, I didn't drain the gas lines. How can I do that? Should I be seeing bubbles or air gaps or anything in any of the lines? I think I have 3 lines?

More ideas always welcome! I want to get me a Stihl, but I think, like all of you, I can probably revive this thing.

Thanks again!

[Bazooka Joe]

Thanks for the replies! I've updated my initial post and put on my flame retardant suit! :D

Anyhow, let's try and figure this thing out. I'm mechanically and technically inclined, but I have little experience with small engine repair.

So, here we go:

1. How can I tell if I have no compression, short of doing a real compression test? I thought pulling on the cord in a certain manner/frequency/... can help determine this??


You can feel it as you pull the pull-start slowly and evenly. If it gets hard-easy-hard-easy-hard to pull, that means there's compression. If you pull and the ease of pulling is the same the whole way along, there's no compression.



2. Techinically, how would the shot of carb cleaner help?


If you've got a weak spark (due to fowled plugs or poor electrical connection), or have a problem with the air/fuel mixture (or water in the fuel) this will "fix" it. What you're doing is creating an explosive atmosphere in the chamber where the spark goes. When the spark goes off, no matter how weak, you'll get an explosion which will drive the rest of the cycle (I don't know how much detail you want, but you're starting the Otto cycle by creating an atmosphere between the LEL and HEL of carb cleaner - very similar to how a potato gun is fired).



3. Checking the spark was something I wanted to do. Any telltale signs I have no spark?


Take out the plug but leave it attached to the ignition wire. Hold the business end of the plug to something that is grounded. You'll see the spark clearly in daylight - are you sure the gap is set correctly and that the plug is the correct type? Is the washer required or not?



I had another post regarding this same machine here, when it was "working" -- but essentially, it ran for a couple mins, or more like 30 seconds or so, and then stopped. Opening the throttle was the only way I could get it to go a little bit more. Seemed like when it had load, it cut out for sure. But maybe this is a clue: I noticed that if I tilted the machine back, that is, make the shaft almost parallel to the ground while I increased the throttle, that helped a lot. If I kept it down (as if normally cutting), and then increased the throttle, it would likely still cut out.

Oh, as for smoking, umm, not so much now. It used to a bit, as well as leave some real oily residue at the back, but I reduced the oil ratio and that seemed to stop. I doubt it's running too lean or rich now.

As for choking, good question: When it cut out, I always had to put it into "A" (full choke I guess), start, then move into "B". It wouldn't run long enough to move it into "C". It would never restart in position "B", even if warm.

And nope, I didn't drain the gas lines. How can I do that? Should I be seeing bubbles or air gaps or anything in any of the lines? I think I have 3 lines?


Sounds like either a carb issue (good news) or a piston/seal problem (very bad news). Both are fixable, but one is way more work than the other. Wether or not you're getting compression is key - no compression = seal problem (maybe starter).

More ideas always welcome! I want to get me a Stihl, but I think, like all of you, I can probably revive this thing.

Thanks again!

[HappyGoLucky]

I'm pretty sure I have compression because I feel the hard-easy-hard-easy when pulling on the start rope. How do I purge the gas lines after emptying all the gas from the tank?

[Bazooka Joe]

I'm pretty sure I have compression because I feel the hard-easy-hard-easy when pulling on the start rope. How do I purge the gas lines after emptying all the gas from the tank?

It's pretty simple, just find the lowest one you can and unplug it (they should all be friction fit, but they may have a fuel line clamp or hose clamp on them). Then hold the trimmer as you would when trimming. There's a very good chance that the motor is gravity fed, in which case you'll drain all of the lines (and tank too) by doing this. Turn it upside down when you're finished.

You can unplug all of the fuel lines too if you want, it will do the same thing. It'll drain faster if you have the lid of the gas tank off. When you turn it upside down and shake it you'll get a last little bit out of the carb.

http://www.odref.com/pdf/Ryobi/2800r.pdf

part #20 and part #11 are the key ones, part #19 won't hurt either.

If you're getting compression, I'd bet dollars to doughnuts that the problem is either gunk in the carb or a clogged fuel filter. What oil to gas ratio are you using? It should be 32:1.

I believe you've got an in-tank fuel filter, it will also be part #20 (the lines, filter and washers are all one unit).

[HappyGoLucky]

Hmmm... do I need to remove 16 and 21 to remove the fuel tank to do anything, or just unplug the flexible fuel line (I do believe they are friction-fit) and let it drain in a bucket?

I assume I can't really get at this fuel filter directly?

What would I do after draining the line(s)? Is there a way to remove any sludge from the filter or anywhere?

[Bazooka Joe]

Hmmm... do I need to remove 16 and 21 to remove the fuel tank to do anything, or just unplug the flexible fuel line (I do believe they are friction-fit) and let it drain in a bucket?

I assume I can't really get at this fuel filter directly?

What would I do after draining the line(s)? Is there a way to remove any sludge from the filter or anywhere?

To drain the tank, just pull off the fuel line. Fuel will leak out into whatever you've got to collect it. If you spill any on asphalt, make sure you burn it off, otherwise it will eat it.

To replace the filter, you'll have to remove the tank in all likelihood. You've got the thing in front of you, so you'd know better than me if 16 and 21 is all it takes to remove - it kinda looks that way from the grainy service manual scan.

From the looks of it though, you remove the tank, take off the line, and remove whatever that little black thing is holding the filter snug in the tank. It could be a washer, a nut or something else. You'll figure it out. Then push the filter into the tank from below, and turn the tank upside down (or grab it with pliers). This is all a guess, you'll have to figure it out as you go - it's not rocket science.

Filter cannot be cleaned, must be replaced. The carb will need a cleaning if replacing the filter doesn't work.

You could have probably drained the fuel and replaced the filter in the time it took me to type this out (and I'm a fast typist). It's a pretty easy job.

[HappyGoLucky]

I decided to try one thing again, and that was to properly regap the old sparkplug. Wouldn't u know it, it sputtered to life again! :D It was late, so I didn't run it for more than a few seconds, but still much better than never-start.

Before I regapped it, I noticed the gap was extremely small -- maybe about 1/3 the recommended gap of .5 mm.

So, the question is, is how did this gap shrink? There didn't appear to be anything noticably "wrong" with the tip of the plug. Can the piston be contacting it somehow?

Thanks!

[canabiz]

Hello, I am bumping up an older thread. While I don't have the same problem as the OP, my gas trimmer (Yard-Man YM75) wasn't working well today.

I turned it on and it's all fine and dandy but when I pulled the trigger to rev up the engine, the bump knob fell out and when I picked it up and pushed it in in a clockwise direction, the knob wouldn't stay in.

It looks like the foam seal is gone. Is it something I can pick up at Canadian Tire? I bought the trimmer second-hand last year so it's not under any sort of warranty.

Thanks

[HappyGoLucky]

:D Me again with another issue with this wonderful Ryobi machine!

Sometimes, it suddenly (I don't recall deliberately or accidentally squeezing the throttle further) goes into full throttle automatically with the engine racing and the power switch doesn't cut the engine.

I have to wait a bit and hope it shuts off by itself (power switch off and my finger off the throttle), which it usually does after a minute or so.

Any ideas? Is there any kind of interlock or something that can go bad that will make the power switch inoperable at WOT?

[HappyGoLucky]

:arrowu:

[HappyGoLucky]

:arrowu:

[jed]

You could have a bit of dirt in the carb causing it to go WOT - my hedge trimmer is doing the same thing, I just haven't had time to take it apart and clean it.