Hello all.
I have an Atom (I think it's a domestic model 104) that I bought second hand - and a couple of early Ryobi trimmers.
They all have the same engine. That is, the generation of Ryobi engines that came out after the one that had the rotating black plastic choke, with inlet only carby with no fuel return, and no primer bulb.
The Atom worked fine for a few months. Then it wouldn't start. So I emptied and flushed the fuel tank, cleaned the air filter, and replaced the sparkplug.
Then it would start, but would instantly die when I hit the throttle. I discovered I could keep it running by pressing the primer bulb and manually squirt fuel into the engine. So I assumed the carby was at fault.
I removed the Atom carby - and its two side covers (which I placed on a clean rag on the table) - and washed the carby for some time in a jar of fresh fuel. I didn't remove the mesh screen (I wasn't sure if I could remove it without damaging it) but I did carefully clean the side I could see of dirt using a clean rag. I also replaced the gasket between the carby and engine because it was deteriorated. (I have not replaced any internal carby gaskets yet.)
Nothing changed. It still starts, runs, but won't keep running without hitting the primer bulb.
BUT...
As I said, I have a couple of Ryobi trimmers with the same type of engine. One of them I bought new and have had it for YEARS. I have serviced it several times with sparkplugs, air filters, and replaced the fuel hoses and primer bulb once. It must be due to this preventative maintenance that it has never broken down.
So I thought I would use it's carby on the Atom, to prove if the Atom's carby was at fault. It actually worked for about a minute. But at no throttle, the Atom ran at full blast. In fact, using the throttle had no effect due to it already running flat out.
Then the Atom again started doing the same thing it had done before - with its own carby.
After some unsuccesful fiddling, I decided to put the carby back onto the trimmer where it belonged. I fitted a second new gasket between the trimmer carby and engine. But the Atom's fault had now (kind of anyway) switched to the trimmer!
Now the trimmer starts, runs on choke with no throttle, and runs on half choke with no throttle - but as soon as you switch to the run position it dies. If you start it again and leave it at half choke, you can eventually coax it into high revs by jiggling the throttle. But again - as soon as you switch to the run position (from the half choke position with the throttle still on and revs high), it dies.
I understand I should probably buy a carby kit. But there's two things holding me back. First, the local mower shop's words were "around $30" for the internal gaskets. And it's only $99 to buy another trimmer. I really want to learn how to fix these things myself and not waste $69 by buying a new one. But I'm concerned a carby kit might not be the problem (for either the Atom or the Ryobi trimmer) because the trimmer carby WAS working fine before using it on the Atom.
Any suggestions would be appreciated. I just don't get how swapping a working carby to another engine - and back again - can cause it to cease working.
Also, I was wondering if there's a way to either make your own carby diaphram and whatever else comes in the carby kits, or, if there's somewhere cheaper to buy a carby kit?
Finally, is there another type of carby - something more reliable - that can be fitted to these engines? Or is there a way to prevent the diaphrams from deteriorating? Apart from the obvious, another reason I ask is, I was thinking of using the engine from trimmer #3 (yep another one) to power a pushbike. If these carbys are so easily upset, they are probably not up to the task.
Or if anyone knows... Is there an engine that would be more appropriate for that kind of task?
Thanks for reading.
Last edited by justallan; 12/04/09 09:12 PM.
