OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Ryobi Trimmers & Brushcutters PLT 3043S, bogging down and stopping?

Hi there,
I have so far cleaned the the arrestor on the exhaust, removed the exhaust and checked for blockages, removed the carby and cleaned with some contact cleaner, cleaned the carby screen and reassembled everything.

The engine starts pretty well first time as per normal starting methods, choke, half choke for a bit then normal run. However when switching to normal run on the choke lever and giving the throttle a quick squeeze the engine just bogs down and dies.

I can run it on half choke for a bit but eventually it will do the same thing, bog down and die.

It will sometimes run at full throttle for a few seconds (10 or so) until it bogs down and dies..

Any ideas?

Dennis

I dont know much about ryobis, but I would just replace the wire screen along with fuel lines and diaphragm. Also Blow out the whole carb with compressed air.

Chris, I will be taking on a old school ryobi soon, pparently they arent too bad, sick of throwing away $99 bunnings specials every 6 months.

Dennis those Ryobi units are a common problem with the wire mesh screen in the carby they are that tight a weave mesh they clog up very easy and restrict the fuel flow.

You either replace it or throw it out completely like a lot of mower shops do but myself personally I replace them with the Walbro mesh which is not as tight a weave.

Thanks for the replies gents, I'll start by getting rid of the screen and seeing if my problem goes away, if so I'll source some replacement parts and give it a birthday..

I quickly pulled the mesh screen out and whacked the carby back together and started the old girl up, it still is exhibiting the same problems, fairly good on half choke but dies pretty well straight away upon a squeeze of the throttle in normal run mode.

On the upside it is starting a lot easier then it used too...

Dennis

dennisf6,

You need to adjust your low mixture screw first till it does not die on you when you accelerate and then adjust the high mixture screw till you peak then back off 1/8 turn.

Thanks Bruce,

I just gave that a go and currently the trimmer will run if I ever so gently feather the throttle until full noise. This is a good thing, however, when I back off and then go for a quick stab of the throttle it bogs down and dies.

Is this still related to the L and H mixture screws?

Dennis

Dennis, Try this,

Step 1: Bottom both screws.

Step 2: Back off the 'H' (high) screw one turn.

Step 3: Back off the 'L' (low) screw one and a quarter turns.

Step 4: Start machine then open 'L' screw till you do not have any hesitation (or very little) going up to full RPM'S.

Step 5: On full throttle adjust till the machine is running at maximum RPM'S and then back off the 'H' screw by 1/8 of a turn
Cheers Gmax

Hi Gmax,

Is this possible with the type of carby I have, it has the 2 plastic adjusters for the H and L mixture screws.

Sorry for so many questions.....

Regards
Dennis

Dennis, Looks like you have limiter caps on your carby, try opening
the L screw 1/4 of a turn (from where it is now).
If it bogs down during acceleration it's usually because the L screw is set too lean. (I'm assuming the rest of the carby is clean with good diaphragms)

Cheers Gmax

Okay, so I managed to get this sorted, well kind of anyway.

I pulled the limiter caps off and found the L and H screws and adjusted as describe above. The engine is running near perfect, no hesitation and it doesn't bog down when i stab the throttle.

The help so far has been great..

Now I have some how managed to disengage the drive cable from the cord head, I have no idea how to get it to locate back into where it supposed to go..

Crap......

If you removed the motor from the shaft to do work on it then it is not that hard to correct. All you need to to just get the inner cable and make sure that you put it into the clutch drum and then slide the shaft back onto the motor.

As you are placing the shaft back onto the motor just turn the cutter head so that it locates back into the head section.

Those limiter caps are a nuisance I had a Poulan chainsaw that had splines on the sides of the carby H/L screws. I removed the screws with long nosed pliers then cut a slot in each of the screws so I could use a screwdriver to adjust the carby.

cheers gmax

Wayne they have a special tool (screwdriver) to adjust those screws. I myself got caught out with them a while back and had to purchase yet another tool in order to repair trimmers etc.