Ryobi 790R 'EZ' Gas Trimmer Won't Start

mwright936April 15, 2011

I have recently been having issues with my weedeater mentioned in the subject line. A few weeks ago, I was having trouble with fuel leaking from the gas tank. I tracked that down to an incorrect sized fuel line that was allowing fuel to leak out around it. That was fixed, and there was no more leak.

Two days ago, I went to start it, and it wouldn't turn over. It had just run fine a few weeks ago, so I know the fuel wasn't bad. I pulled the spark plug, and there was crud all over it. I cleaned it up, then left it out with the plug cable attached to see if it was sparking; it wasn't. I bought a new plug thinking that was the fix. Well, the new plug wouldn't even spark, so apparently the problem starts somewhere before the spark plug.

Another thing to note, for a while now, when I pull the cord to start it, it would hang up from time to time. I always figured the pulley that the cord is wrapped around was grabbing or hanging up, but when I had the spark plug pulled out of the motor and pulled the cord, it was smooth as can be. This makes me think something is coming into contact with the spark plug, but there is no physical damage to the plug.

Can someone help?? Is it a plug wire? Any suggestions at all would help. I really don't want to buy a new weedeater!


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Okay, no plug will spark unless grounded to the engine. The starter 'hang-up' is just compression - yank it on through. I have a Ryobi too, and mine also is hard to start. The reason is fuel starvation for whatever cause. Try this - take the little shroud off the carb area which exposes the air intake - put a few drops of fuel mix in the intake, replace the shroud, engage the choke and it should start. This will get you going, but sooner or later you either have to get a new trimmer or fix that one by overhauling the fuel system. Personally, when they start this I throw them out and get another one (usually 10 years or more). They're not worth taking to a shop and the crummy little carburetors will drive you crazy. I'm convinced these things are made by devils from hell and are designed to fail. I suppose I'll have to go get an Echo and be done with it. I have an old Mantis tiller with an Echo engine and the thing has been reliable and easy-starting for many years.

    Bookmark   April 16, 2011 at 9:01AM
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mwright: I would say that by the indication of your plug description that blow-by gases and over rich fuel conditions have caused some of your concerns. Pick up some fuel cleaner (concentrated) any brand is fine . Add 2 ounces to your fuel (fresh) and with your new spark plug you should be up and running . Fine tuning of the H&L speed jets is normal with these units seasonally along with ensuring air / fuel filters where applicable are clean . If after cleaning & tuning your not satisfied then as Sax has advised toss it , since compression may as plug has indicated may be down and these units do not lend to rebuilding . I love playing with these Old Units but Echo's are the way to go they are not nearly as temperamental as Weed Eater , Troy-Bilt and Ryobi . If you wish you could also consider Stihl but pricing is Hellish and some Models are just not much better than what you have lol .

    Bookmark   April 16, 2011 at 9:51AM
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Well, obviously I'm not an electrician, lol (plug not sparking). I did try draining all the fuel, rinsing it out with some Seafoam, and adding some to the fresh fuel with no avail. I guess I will tinker with it some more, but it sounds like I'm in the market for a new weedeater.

Thanks for the advice guys!!

    Bookmark   April 17, 2011 at 9:32AM
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