I'm sorry to hear that your lawnboy has let you down.

I would say that that leaning the plug against the cooling fins is more than sufficent for checking the spark.

You should not need a new plug each year in my opinion. I change mine when they look worn down on the electrode tip.

Are you using a champion cj8 or equivalent? That is the correct plug.

I think the CD pack is shot in your mower.
The job is fairly straight forward if you want to give it a whirl.

After you remove the plastic shroud you just need to remove the bolts that hold the metal cooling shroud off and the CD pack lies under the metal shroud. Use a 1/4" socket or nut driver to remove the old CD pack and remember the orientation of the grounding wire. Put on a new one and set the gap by rotating the flywheel toward the new CD pack with a standard business card between the flywheel and the metal part of the new CD pack. When the CD pack draws to the flywheel magnets then tighten the two 1/4" bolts. Remove the business card and attach the wires and put the shrouds back together.

One way to test the coil right away before putting the shrouds back on is to attach the spark plug to the new coil and spin the flywheel by hand. You will need to have someone hold the bail down while you do this.

P.S. be sure to use a nice new business card or if you have a feeler guage the .010 hundreds is the proper setting for the gap between the CD and flywheel. I use a business card all the time with good results. Just be sure that the magnets have drawn the CD pack into the flywheel with the card between.

Neal

Hi Neal:

I've been cutting grass oh, for about 40 years now, and I've got to say that this Lawn-Boy is my all time favorite mower. I really love it and miss being able to use it.

I'm glad to hear that what I tried for testing the plug should've worked. Could there be any reason other than the ignition CDI being bad that this wouldn't work?

I started replacing the plug a few years ago when I was having trouble starting it and I had inquired at the place where I purchased it about having it looked at and since it was spring they were backed up with repairs he recommend that a new plug would frequently cure startup woes. I've been doing it since then, since it's relatively cheap.

I belive that it's currently got a NGK BPMR4A in it. I believe that last year it was a Champion CJ8Y. They don't always have the NGK and I get the Champion.

It makes me feel a little better that you also think it's the CDI.

On the 20th when I lifted the plastic shroud it looked like I'd have to remove the gas tank and the primer button to get the shroud off, is that correct? Or if I drain the gas tank, can I just tilt the plastic shroud/gas tank/primer button back without removing the gas tank/primer button? Also, what about the starter rope? Do I leave starter rope in place and just slide the plastic and metal cooling shrouds back out of the way after removing the screws/bolts?

Your instructions for replacing the CDI are very clear so I don't think I'll have any problems with that part of it. I've got a digital camera so I'll take pictures of everything as I go so I don't forget how it all goes back together.Thanks for the tip on testing the CDI before final assembly.

I see a lot of the messages here refer to their Lawn-Boys being of a particular "letter" series, do you know what series my 10247 belongs to?

Regards,

DewGuy1999

Duraforces were an "E" series engine. I would change out the CDI with no worries of curing the problem. Many of these engines, amoung others LB made, were notorious at giving up an early life, such as your has.

Hey there, my name is Joel, and I'm a service tech at a local True Value store. Absolutely, replacement of the CD pack will fix your problem, on average I replace one in a Lawnboy every day (I ususally see the duraforce coils last 3-5 years). Part number 99-2916 or 99-2911 will work (the difference is only the length of the spark plug lead). It should cost you around $45 or so for the part. The spark plug, as you noted, should be either an NGK BPMR4A as Lawnboy calls for, or the equivalent CJ8Y from champion. As far as removal and replacement, yes, take of the fuel tank/shroud, it should be three phillips head screws. The plastic recoil/blower housing should have two bolts and two nuts, 7/16 and 1/2 inch sockets respectively. Disconnect your starter rope from the rope guide on your handle only. Your mounting bolts for the CD pack are going to use a 3/8 inch socket. As previously stated, .010" is the gap for the coil. Please feel free to post with your results or with any questions.

You can find that coil for around 30 bucks too if you shop around. They can use one of several part numbers. Some are more expensive than the others and they all work.

You pull the primer tube and and gas line off the carb and let the starter recoil spring pull the tank shroud up the starter cord. Then you remove the air shroud to get to the coil, being careful to work the air vane through the shroud opening. While you're in there clean the cooling fins and carburetor/air cleaner/governor area. Sometimes these coils don't fail suddenly - they limp along causing hard starting for years before they expire.

I was having similar problems with my DuraForce last year and this spring it simply would not start. What became apparent is that if the plug wire was not making the proper connection and positioned just right, it would not start. I replaced the plug wire for a few bucks and the problem was solved. It is back to being a one or two pull starter again.

I'll admit I haven't looked at my Duraforce coil, but since when does the spark plug wire come separate from the coil? The earlier coils had the integral wire.

On my '02 model, the plug wire snaps right into the ignition with a clip. It is not integral. To this day I'm not sure where the connection issue was, but replacing the wire ended my starting problems.

By the way, any shop can make up a generic plug wire for you. The clip from the ignition end can be reused and slipped onto the new wire. I believe that there is a "needle" (for lack of a better term) in the ignition that slides into the ignition end of the wire to make connection.

echoman: Thanks for shedding light on my 10247 being an "E" series.

Joel (lbservicetech): I've called 4 places locally to price the CDI and got in the neighborhood of $42.50 - 45.00. Concerning the shroud/gas tank/primer button, I'm assuming that once I drain the gas tank, I can just remove the 3 screws and lift the entire shroud/gas tank/primer button assembly up and back while still leaving the gas tank/primer button connected to the shroud and fuel lines, is that correct? You mentioned disconnecting the starter rope from the handle and I assume just leaving it lie loose while I work on removing the recoil/blower shroud is that correct? Will removing the recoil/blower shroud have any effect on the recoil starter? Like am I going to have to rewind it or anything like that?

fordtech: The best price I've been able to find is $42.50 but I'll try and see if I can do better.

saxman1: So, I need to remove the primer tube and gas line from the carb, but I can leave the gas tank/primer button attached to the shroud? Since I've never seen what's under the plastic shroud I'm not sure I completely understand the rest of your instructions, but will keep them in mind when I get that far.

stinky_pete: From all the pictures of the CDI that I've seen on the net it looks like the plug wire is a permanent part of the CDI. Does anyone know for a fact that it's replaceable on the CDI from my 10247?

Everyone: Thanks for all the help and information you've provided. I'm feeling more like I can do this myself rather than paying someone else to do it.

Dewguy, the plug wire looks integral, but it is held in by a two-pronged clip. You can find this by simply lifting your shroud and having a peek. As far as getting at everything, as I recall you can simply lift the shroud and just lean everything back on the starter rope. I'm not placing bets that your issue is the plug wire, but replacement cost is 1/10th of a CDI unit. I took a chance on the wire because I noticed that it would start fine after shifting the wire position. Good luck.

Dewguy, it wouldn't hurt to disconnect the smaller diameter primer line just so you can get the top shroud some room to move around, you can leave your fuel tank hose connected if you so desire, you should have room to move it out of the way. As far as your rope goes, don't disconnect the starter grip from the rope itself, rather just remove the rope from the guide that is mounted on the upper handle of the mower. Regarding the removal of the recoil/blower housing, it won't damage or disturb anything at all. As far as the replacement spark plug lead, it certainly is possible that this is the problem, however in my experience, that is rarely the case. If you are looking for a sure fix the first time, just spend the 45 bucks and put a new coil on.

Hello all.

Hello dewguy1999. Go For It. You Can Do It! You are a LawnBoy owner.

Good day.

Don't mess with the goshdarn rope or handle. All you have to do is to let the starter spring pull the tank shroud up out of the way after you get it loose. Then, you just put it back like it was and you don't lose the tension on the starter cord.

Okay everyone, I'm officially committed to this (or maybe I should BE committed) since I bought the new CDI. Got a #99-2916 for $42.99 + tax. Hopefully everything will go according to plan tomorrow and I get it installed and get the Lawn-Boy to cutting grass again. Not having actually been under the shroud I'm still a little bit foggy on all this, but I'm sure once I get in there the fog will clear. If I run into any difficulties I'll be back here for additional help, if not I'll be back to let you all know how the "operation" turned out. Thanks again.

The Lawn-Boy is sitting torn apart in the back yard with it's new CDI installed and I still don't seem to be getting a spark. I did as indy452 suggested and spun the flywheel by hand before putting all the shrouds back on and I still don't see a spark. I'm doing this in the shade on a sunny day, does it need to be darker for it to be seen? Does it matter which way I spin the flywheel? Does it matter how fast? Also, is there a secret to getting the recoil shroud back on?

Hello all.

Hi dewguy1999. Please post some pictures of your LawnBoy CDI unit replacement progress.

Good day.

Adapting a tip from another forum for making a test plug with a clip on it. I "MacGyver'd" my own plug clip. I took a small hose clamp, crimped the end of the alligator clip through the slits in the hose clamp, put it around the metal part of the plug and tightened it up. Works good, and can be moved to different plugs if needed.

Anyway, after making up my plug clip and using a piece of rope wrapped around the starter cup to pull the flywheel I gave it try and still didn't see a spark. Hmmm. So, I disconnected the kill switch wire from the CDI thinking that maybe it was preventing the CDI from sending the charge. I still couldn't see the spark. Then I got out last years plug, that was dirty and dark looking, put the plug clip on it and I got a spark! Boy was that spark tiny. So, then I reconnected the kill switch wire and tried it again and it worked again! Then I tried the new plug I bought this season. Knowing that I was looking for tiny little sparks on the cleaner and brighter plug and I saw them. Put it back together, twice because I didn't get the plug wire in the right place the first time, and then cut the front lawn even though I cut it yesterday with the push reel mower.

I'm guessing that on Tuesday, either I didn't have a good enough ground with it just touching the fins or I just didn't see it. I wrongly thought that the spark would be like that on a cigarette lighter. Boy did I learn different. Oh I forgot to mention, it started on the first pull. I love my Lawn-Boy!

Thanks to everyone for all the advice.

Regards,

DewGuy1999

Hello all.

Hi DewGuy1999. Great job!

Good day.

It sounds like I'm having the same problem. I hope to get a new CD tomorrow (Sunday) and get my mower back in the grass! Thanks.

I have 3 of these and several other mowers...
I only put in new plugs every 3rd year.

I do lots of preventative maint thru the year too.

# 1 new plugs MUST be gaped B4 they are installed.
I have found that 1 in 10 are at best "close" to spec

# 2 I clean and re-gap 2 times a year I use MG Chemicals Immersion Solvent P/N 8260 to clean the plugs and a stiff brush check gap before reinstalling

# 3 Twice a season I pull the air filter and clean it out...With the filter off have helper start the engine and spray carb cleaner for about 30 secs into the air intake SLOWLY so as not to stall the engine.

# 4 and where the problems start is last years gas...
Empty the tank B4 you store the mower for off season.
Put new gas in at start of season...Then start at Step 2 above..about 1/2 hr and you are good to go... And for goodness sake do cheek and sharpen the blade the difference in cut will amaze you

runs great starts easy .. hunts idle up and down drives me crazy

Reviving my old thread as my Lawn-Boy 10247 is again exhibiting symptoms of a failing (or failed) CDI, I guess 7-years is pretty good for a CDI. Is the OEM replacement CDI still the only choice or is there a 3rd party alternative now? And lastly I'm now wondering if it makes sense to put a new CDI on a nearly 14-year-old mower (2000)?

Considering how tough a Dura-Force engine is and how the Lawn-Boy 2-cycle is a 'self-cleaning' engine, I guess it depends on the condition of the steel mower deck and the drive system, if so equipped. Plus, with every passing year that you operate a 2-cycle mower, fewer people know that there once existed a 2-cycle mower, so you get more and more 'weird' points with them. :)

saxman1:

Thanks for replying.

It's a walk behind, so, no drive system. I think the deck is in good condition. The last time I cleaned under it I remember seeing some rust but I don't think it was a great deal. As far as I know there isn't any rust through or surface rust on the exterior of the deck. Is there something more that I should concern myself with in regards to the condition of the deck?

Is the OEM CDI still the only game in town?

I've always been one to march to the beat of my own drummer, so, having a "weird" lawnmower suits me fine.

I know - its the kind of thing I like to do too. Sounds like the deck is okay. I would keep on using it. CD pack failures are irritating, but when you consider that most people have to buy a new mower long before 9 years, it seems very cheap to operate. Even if you have put new wheels and axles on at about the same frequency as the CD packs, you really are not spending any money on it. And, you can still find the rear-bagging kits and deck plates (blank for discharging, blocked for mulching).
Other things you may encounter after such long service are crankshaft end seals popping out or just leaking, the need to rebuild the carb and carbon build-up in the exhaust ports and muffler. I always recommend adding Marvel Mystery oil to the gas in addition to your regular oil mix as well as the use of a fuel stabilizer. If you use Ethanol-blended fuel, get the Stabil Marine for Ethanol Fuels. All engines like MMO, in particular the 2-cycles.

saxman1:

Thanks again for replying.

Replacing the CDI is definitely cheaper than buying a new mower. Is it common to need new wheels and axles? I've yet to replace either. I don't know about the axles on mine but the wheels still look to be in good shape even after almost 14-years. The crankshaft end seals, carburetor rebuild and carbon build-up in the exhaust ports and muffler are the kind of things I'm concerned about. I don't really have any experience with repairing engines, 2-cycle or otherwise and I'm concerned that those type of things will require paying someone else to do them and I'm not sure that I want to do that considering the age of the mower.

Did have the same problem ! The coil was looking good after some test
did change the wire (spark plug one) for a old suzuki swift one . Did
cut the required lenght and did keep the original plug on one end for
the spark plug and put the little clip on other end did put some
dielectric grease on the cutted end .. and voila ! Did start on first
pull !!! Pretty sure a lot of broken coil was having the exact same
issue.. the coil itself look fine . but the wire for the spark plug
seems very cheap . Was having spark without the pull cord cover
installed . and non when installed.. so i did figure the wire was
sparking to the engine result of no spark to spark plug !

These threads are old, but I still have my 2cycle Lawnboy, purchased 2000. I will add for those of you that still have one but experiencing problems, the muffler on mine became stopped up and engine struggled when hot. Of course, a new muffler doesn't exist and having purchased a "usable" muffler from Ebay had same problem. Took muffler to (of all places) a diesel repair shop.

Mechanic there said, diesels are famous for stopping up a muffler and offered to have it baked and cleaned. Baked? As in a cake? Not quite he said, bake the muffler which turned the sludge inside to dust and then cleaned out. It WORKED! Muffler was a lot lighter when I reinstalled it.

Started on first pull and didn't bog down when hot! I guess after 22 years of use, it wanted to be cleaned.