# Ryobi String Trimmer wont start



## John Lolli (Nov 3, 2005)

I have a Ryobi string trimmer in the shop that just wont start. It is a CS30 Model 30000. I have spark at the wire end and also the plug is firing. I removed the a/f cover and with (for lack of a better description) a tiny turkey baster added gas to the venturi. Will not even attempt to fire. The spark plug was wet so it seems gas is getting to the cylinder. Used the turkey baster to pour some fuel down the spark plug hole -- nothing. The engine seems to have real good compression. I was going to try and clean out the carb however Ryobi tech told me there is no rebuild kit for this carb. It is a throw away item. All help regarding next steps is appreciated on this one.


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## John Lolli (Nov 3, 2005)

As it turns out, I also had a McCulloch trimmer in with the same problem. I decided to try out some of the archived procedures on the McCulloch and if they worked move on to the Ryobi. They both have Zama carbs on them. I removed the plastic caps (without breaking them), removed the high and low speed jets and the spacer and sprayed carb cleaner in the holes. I then blew them out with about 20-25 lbs of air. I next squirted carb cleaner in the venturi area and also tried to blow some in the carb inlet. I next lightly blew air in the carb inlet. I put everything back together including the plastic caps, primed it, and it started after a couple pulls. I was pleasantly surprised. Well now it is on to the Ryobi. Thanks to whoever did the post on this technique.


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## hankster (Jan 1, 1998)

If it won't fire when you put fuel in the cylinder, it isn't a carb problem. I would check to see if the flywheel key is sheared.


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## John Lolli (Nov 3, 2005)

Hankster -- good thought however the McCulloch was doing the same thing. It would not fire when I put fuel in the cylinder either.


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## hankster (Jan 1, 1998)

A 2-cycle engine does not even need a cab on it to run. We pre-test engines a lot after a rebuild, just hold it in your hand, squirt a bit of fuel in the cylinder and pull the rope to see if it will fire.... no carb of muffler on it. If it don't fire, no use putting it together because something is wrong.


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## John Lolli (Nov 3, 2005)

First, thank you for your responses and help. Maybe I am not pouring enough fuel into the cylinder ?? When the engine fires, will it run for a couple seconds as normal or will there be just a small explosion.


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## hankster (Jan 1, 1998)

It will run for a second or two.


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## John Lolli (Nov 3, 2005)

Well, I took a compression test on the unit and it only produced 60PSI. This was after pulling both 3 and 5 times. Looks like I found the problem. I usually do this test first on any 2 cycle but of course not this time. Looks like this one goes to the scrap pile.


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## geogrubb (Jul 28, 2006)

It could just be a stuck ring, remove the muffler and look through the exhaaust port to see if the cylinder and piston are scored, if they are trash it if not try pushing on the ring to see if there is any flex if no flex it is stuck and you need to get it unstuck which might require taking it apart, sometimes I have gotten lucky by dripping Chevron Trchron on the piston and ring through the exhaust port and letting it set overnight. Have a good one. Geo


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## John Lolli (Nov 3, 2005)

I went ahead and removed the muffler to look at the piston, ring and cylinder. The piston was scored and the ring appeared frozen in the groove. Cylinder looked ok from what I could see. I was surprised that the muffler screen was completely clean -- not even a spec of oil or dirt. Makes me think that this unit was running lean or with not enough oil in the mix. Do you think this is worth repairing for maybe resale ? What might the approximate cost for a new piston, ring and crankcase gasket be. I tried soaking the ring with PB Blaster and then Sea Foam however it would not free up.


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## geogrubb (Jul 28, 2006)

IMHO, it's time for the dumpster, however save any parts you might need for a future fix. Have a good one. Geo


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## Lawnmowertech (Nov 12, 2008)

John Lolli said:


> I went ahead and removed the muffler to look at the piston, ring and cylinder. The piston was scored and the ring appeared frozen in the groove. Cylinder looked ok from what I could see. I was surprised that the muffler screen was completely clean -- not even a spec of oil or dirt. Makes me think that this unit was running lean or with not enough oil in the mix. Do you think this is worth repairing for maybe resale ? What might the approximate cost for a new piston, ring and crankcase gasket be. I tried soaking the ring with PB Blaster and then Sea Foam however it would not free up.


john hate to say this but i have to ask when did you get the trimmer ? as far as the mcculloch what model is the mcculloch ? 

the ryobi does it have a gray shaft or yellow shaft gray would = mtd brand yellow = homelite / tti group brand 

the mcculloch depending on the model i may be able to assist you on it let me know the model of the mcculloch 


thanks 
calvin


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