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cordes26

Lawn Boy 10550 Won't Start

cordes26
13 years ago

Could this be a case of the infamous LB CD packs going bad? Have no spark but the fuel is fine. Spark plug is wet with fuel and tried a brand new plug too.

It ran fine last week, not even a hint of trouble, but now it's a no start condition. Just wanted the expert's opinion before I purchase a CD/coil assembly.

Thanks.

Comments (21)

  • snuffyinatl
    13 years ago

    Thats your problem...mine did the same thing! Was running fine the died and wouldnt start up again...new coil and she is doin fine, but I never use it anymore...I seen a Badboy walk behind I couldnt walk away from.

  • orangedotfever
    13 years ago

    This is a open to run coil. You can take the grounding wire off the coil and try to start it to make sure it's not grounding somewhere from the wire insulation melting and shorting out. You can also remove the coil and clean all the contact points to the frame, the flywheel magnets and the pick-up points on the coil. It's most likely the coil though.

  • walt2002
    13 years ago

    As above plus you can try baking it at 200 degrees for an hour, sometimes that "restores" them but usually only temporarily.

    Walt Conner

  • ewalk
    13 years ago

    If you have tested the plug wire for continuity and put in another plug for testing , I would think that you are correct in the assumption of a Ignition Module / Coil gone South . You could do as recommended and bake the coil to see if it re-fires . Then you will know if the coil is indeed going south .

  • cordes26
    Original Author
    13 years ago

    Thanks to all that answered. I put a new coil/CD module in this morning. Started up on the first pull, but it sure had a lot of oil smoke from all that pulling with no starting. Back to running well once the oil burned off.

  • ewalk
    13 years ago

    Good Stuff !

  • cordes26
    Original Author
    13 years ago

    As a follow up, I didn't mention in my last post that the engine is now "dieseling" when I shut it off. It's a little like some of the cars in the 70's when you shut them off they dieseled. Well that's the trouble I've been having since I replaced the coil. Does not matter if the engine is hot or cold. It eventually stops after about 10 seconds of "putting"
    Thanks for any helpful info. Wonder if it's beacause I bought the cheaper generic coil from rcpw instead of OEM.

  • ewalk
    13 years ago

    Within the Automotive scenerio in the 70's Engine Timing and Lower Compression Ratio's and lower octane ratings contributed to the run on (diesel) issues. Perhaps Orange can chime in since he is the resident expert on Lawnboys.

  • 1saxman
    13 years ago

    I think the most likely cause is carbon deposits in the combustion chamber glowing and supporting partial combustion for a few seconds after turning off the engine. Run 2 oz/1 gal Marvel Mystery Oil in your 2-cycle mix in addition to the regular oil and this will slowly fade away. For a quicker cleanup, you could also add 1 oz/2 gal auto fuel injector cleaner.

  • ewalk
    13 years ago

    Sound analysis Sax ! Along with effective solution :)

  • junebug1701
    13 years ago

    I'm guessing the new coil is producing a much hotter spark. Switch to 92 octane gasoline for your LB. Many manufacturers like Husqvarna recommend at least 89 octane for their 2-cycle stuff. The higher octane should eliminate the dieseling.

  • cordes26
    Original Author
    13 years ago

    Thanks to all for the excellent ideas. Saxman, I'm not too sure it would be glowing carbon particles, since I tested by shutting it off immediately after a cold start and it still diesels. I wouldn't think it could heat up at all in 2 or 3 seconds running from cold start. But I'll try the MMO approach anyway.

  • 1saxman
    13 years ago

    In retrospect, I think the higher octane junebug recommended is a good idea in addition to the additives. I use mid-grade in my stuff.
    Just another note: If you partially release the engine/blade control bail from full speed until the ignition is cut off but the engine brake is not engaged, it is normal to have about a five to seven-second coastdown. These engines are not high-compression. To release the bail completely is supposed to stop the engine within two-three seconds. If yours were still 'popping' during the coastdown, it seems to me the duration would be extended. You mentioned ten seconds, but is that actually timed? Is that with the engine 'free' or with the brake on?

  • ewalk
    13 years ago

    Still have not heard from our resident EXPERT Orange ! Having not I would still think Fuel Quality is the primary cause , especially if not fresh the Octane Rating will be very poor .

  • cordes26
    Original Author
    13 years ago

    The fuel is fresh. In all other aspects it runs perfect.
    Saxman....not actually timed at 10 seconds, just approximately. The brake is fully on (handle bail full release). It sputters during maybe up to 10 seconds until it finally stops. Again it's amazingly like the dieseling run on problems of some 70's cars. I'll try a higher octane next time around. If that doesn't do it maybe I will splurge for an OEM coil. It's strange that this only started after I replaced the coil. Never happened before that.

  • orangedotfever
    13 years ago

    Are you sure that you didn't pull the grounding wire off the coil as you put it back together? If so, you are only getting the flywheel brake to slow the engine down until it finally stalls. You need to ground the coil out through the bail switch to kill it quickly. Check the grounding wire through the bail switch.

  • 1saxman
    13 years ago

    That's probably it. In case it isn't, throw the throttle into 'choke' just before releasing the bail. This will fllod it and help it stop quicker. If the bail is not turning off the ignition, I'm surprised the brake will even slow it down from full blast.

  • ewalk
    13 years ago

    Well there you go Orange has given an excellent point of info as to ensuring the coil is properly grounded to allow proper bail effect . Easy to overlook when installing new coil / cd module . As for Sax's initial scenario as to glowing carbon particulate reigniting residual fuel within the combustion chamber of a two stroke mower , I still believe it has it's merits . I have seen this occur in some early 70's snowmobiles where improper oil to fuel ratio's were the primary cause of this condition. Anyhow interesting trouble shooting scenario .

  • orangedotfever
    13 years ago

    "As for Sax's initial scenario as to glowing carbon particulate reigniting residual fuel within the combustion chamber of a two stroke mower , I still believe it has it's merits."

    It absolutely has merit. Since he messed with the coil, that's the first, and easiest, place to look. Lawnboy grounding tabs also get dirty and sometimes don't ground the coil out properly. My C21ZPN is doing that right now. If it's not obviously disconnected, meter the wire from where it connects to the coil to the cylinder head to see if it's grounding out the coil when the bail is released. Good luck and let us know.

  • ewalk
    13 years ago

    Another Good Troubleshooting Recommendation Orange , numerous times the obvious can fool us . Never trust what appears to be an adequate point of ground !

  • cordes26
    Original Author
    13 years ago

    Thanks to all for excellent suggestions. I'll try and have a look at it over the Thanksgiving Day weekend. I'm 99.9% sure the ground is attached properly, but you never know if I overlooked the obvious. Like I mentioned, it just sputters some, not running with full ignition when the bail is released. I'm not sure if the brake can overcome that if full normal ignition. Will let you know what I find out.