2 cycle Ryobi tiller

[MarineBob]

I have now declared a quest. I have an old (ancient perhaps?) Ryobi tiller/cultivator that used to run OK. Last fall when I went to turn over my garden, no go. I figured I'd get to it as a winter project. But here we now are, almost tomato season and I dug out the tiller. No go...... So here's what I did

New spark plug
Fixed crack in fuel tank
new fuel lines ( I am sure I have them connected right)
new primer bulb
new fuel filter
carb rebuild, then a new carb
clean up of coil and flywheel 'contacts' (I think I got clearance right, about 010)
new gas mix

Pull, pull pull......the best I could get was a short run burst on starting fluid. But only one time........with spark, ought to pop with ether.

Checked the spark plug lead , checks OK with a tester, with plug out, got spark across gap and plug grounded
removed lead from shut off to make sure it was not shorted

I am now pulling my hair out

Only thing I can now think of is can the magneto be weak and not fire the plug when it is installed? I will go back and check flywheel, coil gap but I am not sure how much difference that will make just to get engine to pop? I read about the flywheel magnets can get weak? But they seem pretty strong....they grab a screw driver vigorously

Anybody got any other ideas? This is now a quest...

When I put in the new carb I opened the mixture needles about 1 3/4 turns.

 

[MarineBob]

FWIW……Finally got to the root of the problem. Should have been no 1 or 2 check. Checked the compression and got 30-35 lbs. should in the 90+ range or higher. Took apart the cylinder head to find the piston ring frozen-corroded into the groove. I guess you shouldn’t let the machine sit in a shed for a couple of years. I tried all sorts of stuff to free the ring to no avail. Heat, solvents, penetrating oil. When i gingerly tried to loosen it, broke into several pieces. I have several old Ryobi trimmers with the same 31cc engine so i swapped one of those pistons. 4 or 5 pulls and I was tilling the garden.

 

[MarineBob]

To finish my story....... As noted, I got the tiller running with a piston/ring from another same Ryobi motor. Being a cheapskate I hate to throw anything away. I went looking for a new piston ring for the old Ryobi. I got suggestions and I called Ryobi who sends you to MTD and Yardman these days for old Ryobi equipment questions. MTD rep, while very helpful, referenced a new piston ring for $45....just for the ring. I suspect it might have included the head and piston but was told.....ring only. Anyway, after some measurement, I found the piston was a 35mm and the ring was about 1.6mm.....actually, 1.5mm square. After an internet search I found lots of suppliers. I ended up with a ring on Amazon, 2 rings for $6 and change......I had to file the ends a bit to adapt it to my Ryobi which has some sort of small pin in the ring groove (not sure why) but its a good fit and it fits my budget. So I guess the lesson is check the compression when nothing happens and you have confirmed spark and fuel. And don't let you tools sit for a couple of years in the cold and damp with some preservation. work done first. I am sure a squirt of oil into the cylinder would have saved all the consternation

 

[He who knows]

Make sure to tell her-that-scowls-at-you that one of the bits of old stuff you've been keeping in case it comes in useful came in useful.

 

[MarineBob]

Sir, you are quite right, but I am not suicidal...LOL

 

[He who knows]

I was lucky a couple of years ago - at the start of all the lockdowns my wife wanted a raised planter on legs to grow salads etc. Apart from the fixings and the poles+anti-bird netting, every single bit came from the "might come in useful one day" stockpile

 

[MarineBob]

Next lock down I might get to the three wheel barrows in my stash……one has good arms, One has a good tub…….one has what appears to be a serviceable wheel/ tire….well, maybe need a tube…. Some day