Spark

Discussion in 'Electrical' started by 45u, Mar 31, 2016.

  1. 45u

    45u Active Member

    I only get a very thin spark not as blue as I would like and it will not start. It has not even popped. I have even replaced the CDI and stator not any better? I have even put gas down the plug hole and still not even a pop. I have tried holding it wide open in case it is flooded. Sure does not seem to be a really good spark like on everything else I have ever worked on! I checked the air gap between the rotor and stator to make sure it is not hitting on one side and I tried two NEW NGK plugs. Any suggestions?
    Thanks
    Jeff
     
    Last edited: Mar 31, 2016

  2. crassius

    crassius Well-Known Member

    spark is always a bit thin at cranking speed - check that gaskets and seals are good and no air leaks at carb - if this is a new motor, it has to be something simple
     
  3. 45u

    45u Active Member

    I took the whole motor apart before I even turned it over because of all the shavings and trash inside and I see why they want you to run it so oil rich when new to flush out the trash. I torqued the cylinder nuts to recommended specifications. Do to the tight fit I started out with a SHA clone carb. There is gas in the exhaust pipe and in the cylinder and has compression. It has never popped so I would think it has to be fire. I even replaced the WHOLE ignition system. I have 4 NEW plugs with the gap set at .025 and the ignition will only make one of them spark. I have the rear wheel off the ground so I can turn the motor over and check spark. I get it going at least as fast as I would riding it and popping the clutch. Last night I ordered ANOTHER ignition system and if this does nothing I will order a new rotor.
    Thanks
    Jeff
     
  4. crassius

    crassius Well-Known Member

    not sure what 'whole motor apart' means, but there are a LOT of mistakes that can happen with rotor timing, seals and gaskets if everything was apart

    maybe once in 100 motors do I see something in the motor that shouldn't be there, but usually not something serious - if you do get a new motor, leave it together
     
  5. 45u

    45u Active Member

    Little back ground on myself. I have been riding and working on including but not limited to machine work on motorcycles for over 40 years much of the time as s living. If you give me a shout out crank and a rod kit I can build that as well. When I said take apart do to all the grit and dirt in the motor I went as far as split the cases installed all new gaskets and torqued to recommended specifications from here. I even had to flush and lube the rod bearing as it was stiff till I did this showing it all so had dirt in it. I SEE WHY THEY WANT A PERSON TO RUN SO RICH WITH OIL WHEN NEW. Just one of my many babies. LOL
    Thanks
    Jeff
     

    Attached Files:

  6. crassius

    crassius Well-Known Member

    my first guess then is that rotor is on backwards - with key way at 1 o'clock, check that rotor is almost exactly horizontal
     
    45u likes this.
  7. HeadSmess

    HeadSmess Well-Known Member

    ditto that, but its so obvious really, that surely someone with 40+ years mechanical experience, including making cranks etc, couldnt possibly make such a simple mistake.
     
    Timbone likes this.
  8. crassius

    crassius Well-Known Member

    for someone new to these, the info on timing may be hard to find
     
  9. jaguar

    jaguar Well-Known Member

    replace the magnet that powers the stator coil.
    also remove the shellac from the stator coils mounting screws. they provide the ground path from the spark plug to the ignition system and anything less than perfect raw metal to metal contact there will provide unwanted resistance to current flow.
     
  10. Wolfshoes

    Wolfshoes Member

    Recently I purchased a replacement magnet on ebay to troubleshoot a performance problem. The engine is a 2011 build Grubee Skyhawk 66 received in 2012.

    magnet comparison.jpg

    The magnet on the left is the original marked out to prevent reinstalling it backwards. The magnet on the right was shipped from a vendor on ebay. Just from visual inspection without even taking a measurement is is apparent from the key slot positioning that the timing would be different. I contacted the vendor pointing out that from what I know about the motor his part would advance the timing a great deal and this could damage the motor. Therefore, he should not sell this part as a generic replacement. The vendor responded that the picture of the part on ebay was information enough about the compatibility and was offered to return my payment if I returned it. No shipping reimbusement.

    I have heard before the wisdom of buying parts from the manufacturer of the motor but I have been having good luck, if not better luck, buying parts on ebay. The magnet is a married setting to the crankshaft and if any part has to be bought from the original manufacturer it's the magnet. Since the positioning of the key slot is so critical it raises the question of is this even good enough. The case is made for having a adjustable CDI ignition.
     
    Last edited: Apr 2, 2016
  11. crassius

    crassius Well-Known Member

    true, that I'm occasionally seeing those rotors marked 'out' in your pic - I doubt they would fail if reversed

    my info about the 1 o'clock setting is for the second type which can fail if reversed
     
  12. 45u

    45u Active Member

    Mine came with a rotor that looks like the picture on the right. A big thanks to all as I think the rotor was on backwards and will no for sure tomorrow. Being night I turned off the shop light and turned of the motor with the pedals and I have a bright continues blue spark just not as fat as I am use to.
    Thanks
    Jeff
     
  13. 45u

    45u Active Member

    THANKS EVERYONE!!!!!!!!!!!!! After turning the rotor around she bust right off.
    Thanks
    Jeff
     
  14. crassius

    crassius Well-Known Member

    always the simple things when there are only about 12 moving parts
     
  15. 45u

    45u Active Member

    Yes and I have touched everyone of them in my motor.
    Thanks
    Jeff
     
  16. 45u

    45u Active Member

    In the past two days I have run half a gallon throw it. Some problems one being a stator died. Started buy misfiring when hot then died. Then it seems I am having to adjust the clutch a lot. I am impressed with how well it does pull my old big butt! Need to work on better or more brakes.
    Thanks
    Jeff
     
  17. crassius

    crassius Well-Known Member

    you'll find that clutch cable & chain will stretch a LOT in first week or so
     
  18. Greg58

    Greg58 Member

    Jeff don't use the springs to return the clutch shaft arm as shown in a lot of kit instructions, compressing the spring will stretch the cable. The large internal spring is more than enough.
     
  19. 45u

    45u Active Member

    Yes I put it on but not doing anything right now do to the way it is adjusted. I am not too worried as in the past 3 days I have run all most a gallon throw her and she is running well even with all the hills around here and my big old butt at 230 pounds. LOL
    Thanks
    Jeff
     
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