Lawn Boy 2 cycle coil replacement

Discussion in 'Mechanic and Repair' started by subeedude, Oct 24, 2009.

  1. subeedude

    subeedude LawnSite Member
    Messages: 12

    Hey fellows,
    I just paid a local shop about 180 to replace the coil and take off and clean the carburetor on my 2003 Gold Series 2 cycle. I was wondering a couple of things: 1. Is that a fair price (I didn't think it was outrageous)? 2. What makes the coil go bad? I don't use the mower that much any more as I have been using some battery mowers since I have a small lawn, and actually I only kept it to mulch up the voluminous amount of leaves that I get on my lawn in the fall. A third related question / comment is about the coil on my 10-15 year old Toro 2 cycle Tecumseh snow blower, which sometimes can skip a season and get relatively rare use here in Mid Missouri. I had it replaced a couple of years ago, and the shop told me that coils go bad from lack of use. Anyway, it ran okay for one season, and the next season it would run good for awhile, die, not start for awhile (cool down quick in the freezing temps), and repeat that scenario until it wouldn't start again. Finally, I just drained it and stuck it in the shed. Puzzled and aggravated the sh*t out of me. Now I'm thinking that I should take it in to get it repaired, and I'm betting they are going to tell me I need another coil, which I assume I could replace myself for a lot less money. The first five years or so after I bought it, you could count on it starting about the third or forth pull each winter. Now, when it does start, I about yank my arm off. Any advice appreciated.:dizzy:
  2. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    1. I don't know about fair but that's around what they charge, you didn't get ripped off.

    2. TIME is probably the worst enemy for most electronic devices, best answer I can give you, whether it runs or not, they go bad over time.

    3. The coils themselves tend to run between $50 to $80...
    They're not hard to replace but you HAVE to set the gap proper or it will NOT run!
    Yes, there is a tiny gap between the coil's pickup and the flywheel magnetos...
    If the gap is too big, it won't create a spark.
    If there's no gap, it either won't turn over or it will destroy that coil in very short time.
    Most folks use a spare business card or similarly thin flap of cardboard to set that gap, after lining up the magnetos to the coil's position.
  3. subeedude

    subeedude LawnSite Member
    Messages: 12

    I don't get it. How does "time" degrade the coil or other electronic device but especially small engine coil? Has to be more than just time. What happens to them during the time they go bad if they are not being used???

    Second, I think you just scared me off on replacing the coil myself. I didn't know that you had to adjust any gap. I always figure if you don't know what you're doing you just screw it up. Thanks!
  4. Breezmeister

    Breezmeister LawnSite Bronze Member
    Male, from South Jersey
    Messages: 1,761

    It's not hard to replace a coil, there are plenty of threads on here on how to do it correctly

    Then how do you expect to learn ?
  5. subeedude

    subeedude LawnSite Member
    Messages: 12

    Good point: Then again, after dropping that $180 to replace the coil; remove, clean and reinstall the carburetor, that baby fired right up on the first pull and I used it all afternoon. If I had done it, I may have spent all afternoon fiddling and cussing and never got the yard cleaned up. I think that after I retire and have more discretionary time, THEN I will for sure take your advice. :)
  6. Roger

    Roger LawnSite Fanatic
    Messages: 5,941

    I used LB 2 cycles for years, and replaced several ignition modules. It is an easy task, taking about 30 minutes on the outside. A new unit was about $50, if I recall correctly. It just takes a few simple tools and a feeler gauge to set the right gap. A business card will do in a pinch.

    The question is not how hard/easy to make the replacement, the bigger question is when. It is not like a broken handle, a wheel support that is broken. It is not so easy to know the module has gone bad. My assessment was typically related to hot starting problems. In other words, the engine started well when cold, but didn't start well (or at all) when hot. I had so many other starting problems with my DuraForce, it was hard to distinguish between ignition module failure, and other issues.

    The ignition module is an electronic device, subject to quirky failures. One might last a very long time, another might last a short time -- through no fault of maintenance procedures on the machine.

    I'm glad my DuraForce is parked -- probably permanently.
  7. ae lawn and snow

    ae lawn and snow LawnSite Member
    Messages: 16

    i read somewhere that it is moisture that gets in there and shorts out the wiring. i have also had luck with heating the coil legs with a propane torch and that makes them work for a while (2 for 2 so far!). Google search "coil baking" or something and theres alot of info. A trick for setting the air gap is to use three thicknesses of notebook paper which is about .010 which is recomended.
  8. Gyrobob

    Gyrobob LawnSite Member
    Messages: 15

    I have used them for a while as well. While I do love these things for all the day to day advantages of the 2-stroke motor, one of the design defects is the ignition coil.

    A permanent fix that works 95% of the time is to take off the coil, seperate the plug lead from the coil, clean and derust the coil, put the coil in an oven and let it bake for about an hour at 170-200 degrees. When no oven is available, just letting the coil sit out in the sun on a hot surface (the top of a black garbage can, etc.) for a few hours will do the trick. Then give it 2 or 3 coats of tough clear spray paint (clear wheel coat, clear engine enamel, etc.)

    Usually that will give you a coil that works for the life of the mower. I shudder to think how many of these coils were tossed needlessly.

    One other item to check on reassembly is to tidy up where the plug lead fits into the coil. Cut off the last 1/8" of the plug lead and sand it or something to get a really clean, straight end. I just use a belt sander and sand off an 1/8" or so. Clean out the hole in the coil where the lead fits in. Really clean it -- choke cleaner, carb cleaner, alcohol, etc. Also check to make sure the sharp little "blade" that gets inserted into the plug lead is there and straight so it'll stab the plug lead properly right into the conductor wire. Then carefully insert the plug lead and snap the plug lead holder into place on the coil, making sure the plug lead holder has moved up the plug lead a distance equal to how much plug lead you cut off. The idea is to get the plug lead inserted all the way into the coil. Sometimes the factory is not real precise with this.

    I'm glad my Duraforce is fully alive, well, and not parked.
  9. Gyrobob

    Gyrobob LawnSite Member
    Messages: 15

    All that is good guidance, but after about 45 hours of use on the coil that I baked and clearcoated, it has started acting up again. The only way I can get it to work is to heat the coil up with a hair dryer for about 10 minutes, put the cover and shroud back on, then start it up. It'll run for hours and hours that way, but after it cools back down, sometimes it won't start,.... unless I heat it up again.

    Now I'm looking for a coil that will fit that is not a Lawnboy/Toro part,... something made by an aftermarket manufacturer.

    Got any ideas?
  10. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,248

    Take a look at your yahoo email, Gyro.

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