I just converted a ryobi 31 cc got it back together but am getting no spark, I tried the card trick on the coil, but still no spark, I did not hook up a kill switch, would this be the problem? what is the proper gap on the stock coil?

Flywheel to coil distance is .010 thou. Mag igns. have to be cranked pretty fast. and not in sunlight to see the spark. Kill switch not needed for testing.

I think a mag. needs about 300-400RPM to generate a spark.

Pull the plug and lay it against the head. Hook your cordless drill to the crank and spin it with the drill in reverse. You will quickly see how fast you need to spin it to make a spark.

Thats why electronic ignition is so nice. It sparks at any RPM. Makes for very easy starting and a silky smooth idle.

Hi Ave8or;

I have just converted 2 ryobi's 31cc for a B25. They will not spark when flipped over by hand, I need a starter or drill works too. I find that weird.... two of my other conversions have lots of spark when flipped by hand another one is like these two ryobi's and need a higher rpm. It is a 42cc. and I changed coils from various other weedeaters but the same thing. For a while I thought it was the diameter of the flywheel, but I measured them the other day and they all vary shooting that idea all to hell.

I would like to know why some start by hand and others don't if it is not the coil. Any idea's??


Peter

I believe when they were set up for chainsaws. If they wern't cranked fast enough, they would kick back and snap the starter rope. So they made it have a higher cranking speed to get a spark. When I had the saw shop before I retired, there was a small module to change points ign. to electronic ign. The first modules that came out sparked at to low a speed so the changed them for this reason. I bought all the older modules they had, but used them all up and couldn't get any more.

Thanks Flypaper 2;

That kinda answers things. I have a old Stihl 54cc. on a spitfire and it had points, so I got one of those little modules on it, they only weigh a fraction of an ounce. It works great, hand starting is no problem, but....... I also have a Ryobi 26cc. with stock coil, it hand starts no problem, are you saying it is buit into the coil?. There is no place to put the module on the newer coils. I changed the coils on my 42cc. with numerous others, some I believed sparked at low rpms, but it made no difference to that engine.

So is it the coil?. If so is there an id number for the older lower rpm type coils?

Thanks guy's Peter

By the way how did you make out Ave8or

Yes, Peter, the trigger electronics is built into the coil and the little module cannot override it. You might try running the coil as close to the flywheel as possible without dragging on it to see if that makes a difference, as you get a stronger magnetic field. If it's the RPM that triggers it, then it won't work.

Hey.
The real thing here is if the engine sparks or not.
Sometimes we can´t see the spark but it is audible.
I have 3 ryobis working great and all starting by hand. The secret is a proper choke, they liker to start when the carb is filled up with the choke pump that comes in the trimmer.

In a uncowled engine I choke it with a finger until it gets fuel wet, then it starts at first or second flip.

Try it.

Tato Lazo.

Hi Tatolazo;

I know what you mean I have given that advice myself. On some engines though you can flip that thing till the cows come home and you will never start it, yet touch it with a starter and away it goes.

I would like to know how ave8or made out....... are you there?????

Sorry peter, took so long to reply, I laid the plug on the head and cranked it with my 12 V starter but still no spark.

What the heck is wrong?, the engine ran fine before the conversion, also I was told that this engine can be started with a standard starter, that must be wrong, I put the plug in and my starter won't hardly turn it over.

Hmm...
I can pull the cord on my weed wackers (all 3 are ryobi) with a very light pull and see a rather strong spark across the plug with just one rev past TDC.
Hell, I've always seen that on any magneto type engine I've ever checked. Briggs, Homelite, Ryobi, Kohler, Techumse...
It don't take much more than a little pass of the magnets to kick the coil.

I've seen lots of folks stick a screw driver in the wire and hold it by the head. This is ok, but I seem to get better results by taking the plug out of the head, which releaves compression, and put it in the wire. Then you can hold the wire (unless it's cracked, then it will add some spark to your life ) and press the plug threads against the cooling fins of the head. A light pull on the cord, or in this case, flip of the prop and snap... spark!

Tom

You mentioned the ground wire on the coil.
Normally, this is to shut it down by shorting the Pulse, generated by the magnet passing under the coil, to ground.
If I'm not mistaken, the opposite could be true, if the Iron core of the coil is not grounded, it might not make a spark.
Generaly, I've only see the Phateon (I think that's correct) coils on my Ryobi's. They all have a spade bayonet sticking out of the coil.
If you short that to ground, it wont spark.
Also, if you have an ohm meter, the coil should read 200-300 ohms from the iron to the bayonet. You will know the ground is good if you measure from the core to the head and it's 0 ohms.

Hope this helps,

Tom

Hi Ave8or;

Sorry to hear you are having trouble. The ignition system is pretty simple. If you have your coil spaced correctly from the flywheel and the coil is good, you have spark. Purhaps you could check the gap from the flywheel first, if not try another coil. It is even possible you have partialy pulled the ignition wire away from the coil and are not making contact.

As far as starting goes, I use a drill when bench testing, but at the field I have a starter from an old garden tractor. It is not that much bigger around but will start anything out there..... well have never tried 100cc or above.

Hope some of this is usefull. Peter

PS. curious to see what you get for rpms. so I can compare it with mine.

Have you tried a new plug? Sometimes when a plug fouls the voltage can leak off across the insulator and will never spark (jump the gap).

Steve

OK, let me take back what I said.
While I can get a spark with the rope on a weedy, I can't get one by flipping my prop. (just finished stage 1 of my first Ryobi)

I have the stock flywheel behind the prop for now, but my poor little hobbico starter won't flip that big monster. (single ring type)
The motor is WELL broke in and ran like a champ as a weed wacker.

Here is what I did to start it:
I have a few cargo straps for my little trailer. They are about an inch wide. I had one that was torn so I cut about a 5 foot length of it off.
Holding it tight to the adapter between the prop and the flywheel, I wrapped the strap as tight as I could around the adapter; 5 times around.

Turn the ignition on, grab the strap a safe distance from the prop and angled slightly away from the prop, pull and zoom, she was off and screeming.

Apparently speed accross the magnets is the key after all, RCpilet must be right

Good luck and be safe.

Tom

Hey guys just a bit of experience from and OLD mag guy, a mag ususlly requires more speed (rpm) to create a good spark than a battery powered coil setup. But also a good magnetic path between the fly wheel and the end of the coil core. Try sanding the end of the coil core and the outside dia. of the flywheel or the flywheel magnets and make sure there is no rust as that will disperse the field and prevent a good spark and this is the trouble more times than not.

If you have access to a good solid state multimeter like a Fluke or Beckman Put it on the highest ohm scale and measure between the center and case of the plug when it is out of the engine. Any reading at all means the plug is leaking and will degrade the spark a lot. Make sure your fingers do not touch metal on both connections or you will read you and not the plug leakage.

I hope that some of this helps, if someone wishes to inquire futher please e mail me at [email protected] as I seem to have a real hard time returning to these places when I want to and no trouble at all when I do not, HI HI.

please excuse the spelling but I am from TEXAS

fly the airplane first

73 Lee K5MRC

Just a though....
I use a carburetor cleaner as a primer.Just a tad of it in the throat of carburetor and it fires real easy.I havent finished my conversion but would imagine it will help it too.Anything contains ether will ease the job.

Mitty

If I'm not mistaken (I very well could be...), ether will fire on compression alone, right? Seems like a shot of starting fluid or as Mitty said, carb cleaner might be something to consider. I'm just waiting on a prop, and the last few steps in finishing up the airboat hull, then I'll see what this conversion business is all about. I have my old Homelite XL chainsaw engine ready to go. It too still has the stock ignition, we'll have to see how well it works out. I'll know in a few days hopefully. It's just 1.6ci in displacement, so I'm hoping that my 12V electric started will spin it, if not I'll try the drill trick.

I don't think ether (or anything for that matter) will fire on compression alone in a gassoline motor.

You need spark.

Tom

carb cleaner will wash the lube off moving parts........use starting fluid.....the brand that says lube added. Good luck Capt,n

http://www.harborfreight.com/cpi/cta...emnumber=36258

is a neat inline ignition checker that flashes a neon light with the spark. I use mine quite often. Works for both magneto and electronic ignition.