How to fix Ryobi RLT254CDSO 2-Stroke Line trimmer head not rotating?

Question

Hi everyone,

I have a Ryobi RLT254CDSO 2-stroke petrol line trimmer (manufactured 2021). The engine starts and runs fine. However, when I press the throttle lever to cut grass, the trimmer head does not rotate.

Here’s what I’ve checked so far:

* I opened the upper shaft section and confirmed that the top half is rotating when the throttle is pressed.
* The lower shaft is an expandable attachment type, connected with a pin lock.
* I removed the inner drive cable from the lower shaft, and it appears to be broken at the bottom end.
* I attempted to open the bump feed head but couldn’t figure out how to remove it.

My questions:

* Does this sound like a broken lower drive shaft cable?
* If yes, do I just replace the inner flex cable, or do I need to replace the entire lower shaft attachment?
* How do I safely remove the bump feed head on this model to inspect it?
* Are replacement parts (drive cable or lower attachment) available at Bunnings?

I’ll attach photos of the shaft wire and the head for reference.

Any guidance on the next steps would be greatly appreciated.

Thanks in advance!

MitchellMc · Answer

Hi @nik25,

The Expand-It accessories typically suited both the petrol and 36V range, which had split shafts. It would be best to take your machine in with you so the Power Gardening team can verify correct fitment.

Mitchell

nik25 · Answer

Thanks @MitchellMc for your inputs and suggestions. The attachment available in Bunnings does not mention specifically that it supports 2 stroke petrol versions so I was not sure if the attachment would work. The attachment mentions below in terms of compatibility- “This Line Trimmer Attachment is part of RYOBI’s range of Expand-It attachments compatible with the RYOBI 18V and 36V Expand-It Powerheads”.

Can you confirm if this would fit in my petrol 2stroke line trimmer?

https://www.bunnings.com.au/ryobi-expand-it-45cm-line-trimmer-attachment_p0606530

MitchellMc · Answer

Welcome to the Bunnings Workshop community @nik25. It's wonderful to have you join us and many thanks for your question on Ryobi line trimmers.

From what you’ve shown and the fact that you’re able to withdraw the inner drive cable from the lower shaft, it is evident that the lower drive shaft has snapped. The flex drive cable should normally remain engaged within the lower attachment. If it can be pulled out freely, that’s a strong indication it has failed. From your image, it appears the cable has sheared off.

While it is technically possible to order a replacement inner flex cable, the key question is why it snapped. Drive shafts typically fail due to a sudden and violent stoppage of the head (for example hitting a solid object), lack of lubrication, or wear within the head gearbox or lower shaft assembly. Without confirming the root cause, simply replacing the cable could result in another failure if there’s an underlying issue, such as internal binding or worn components.

Given that this is an expandable attachment model (the Ryobi RLT254CDSO 2-Stroke Line Trimmer), the more practical and reliable solution would likely be replacing the entire lower shaft and head assembly. The Ryobi Expand-It 45cm Line Trimmer Attachment is compatible with the Expand-It system and would replace the complete front section, eliminating any uncertainty about hidden internal damage. If you prefer a curved shaft version, that can usually be ordered through your nearest store’s Special Orders desk.

Regarding your other question about removing the lower head, I believe if you remove the guard and inspect behind the head, there should be a locking fixing, that when undone, allows you to remove the head.

Please let me know if you have any questions.

Mitchell