Motor not running

inked1974

inked1974

Member
Not sure if this is the proper area to post but thought it may be best.
Well here goes, built my bike with a used craiglsit purchase 66cc. Bike ran great for 8 months. no issues besides the normal loosening of bolts. One day at WOT motor just died, kind of like it lost all spark.Bike would sound like it wanted to run while peddling but no "POP". Pulled the plug and found a very rich coloration. Changed plug, changed oil ratio from 25-1 to 30-1 and didnt start, changed cdi, didnt start. Had another unknown 66cc motor on the bench that was in almost perfect condition. Swapped it out and BANG away I went. Ran extremely well for about a 20 min ride and then bluhhhhh. Same issue. Again I checked plug and it was very rich. with this new motor ( pictured below) I have now done the exact same swaps of parts and found no improvement. I did however find that this motor did not have a head gasket, only some blue sealent that was barely there. so i installed a head gasket. As you can see by the pictures, I did begin with an intake manifold that made the carb level, I then tryed 2 other intakes wich made the carb not level. i am currently back to level. If there are any more pictures that would be helpfull to pinpoint an issue please let me know. I have done the following in an attempt to repair.
1) new plug
2) new CDI
3) new magneto
4) new head gasket
5) checked jet for clogs and cleaned carb (really wasnt dirty)
6) tried to run without exhaust and with standard pipe
7) scoured motor for any possible air leaks (found none)
Note: The only part that was on both motors was the NT carb and please excuse the taped up cdi and the bare wires, I wanted to show my wiring conection and mount the cdi for quick removal while figuring out my issue. Thank you in advance for your help!

:-||
 

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Neither motor was wired with a kill switch. I forgot to mention that sorry. Also, I did check for spark when i installed the new plug and thought I saw a spark. However it was daylight and i was fighting to see it and out of pure frustration I could have convinced myself that I saw one. I will surely try again with the garage lights turned off. Thanks for the suggestions guys.
 
inked1974 said:
Neither motor was wired with a kill switch. I forgot to mention that sorry. Also, I did check for spark when i installed the new plug and thought I saw a spark. However it was daylight and i was fighting to see it and out of pure frustration I could have convinced myself that I saw one. I will surely try again with the garage lights turned off. Thanks for the suggestions guys.
Click to expand...
If you use a small amount of throttle body cleaner and squirt into the carburetor, if its going to start then it will. I don't peddle (have 15% of my heart working) to start my bike cold, I start with a squirt of TBC...been running the engine over a year.
 
If you have a fresh spark plug gap it between 0.017 to 0.020.
With the spark plug removed and laying on the head so you can see it spin the rear wheel with the engine's clutch in the run position you should see a nice blue spark. Your problem could be a bad connection in the ignition wires to take care of that solder all connections. If your using crimp connections soldering the wires in the connectors will not hurt a thing.
I looked again at your photos the wiring connectors will work but aren't the best. Could be you might have a bad ground wire. The black wire where it connects to the magneto frame.
There's tests you can do with an Ohm meter to check the mag and coil you will have to do some looking I don't remember just where they are at.
Make sure the white wire is not touching anything and capped off.
 
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All information soaking in! I will pull out the volt meter and document some numbers. I pulled a chart from another one of your threads to compare to. Thanks again for the suggestions. I will post my findings in the morning or a picture of me going by the camera at 30mph.
 
Hey inked, sorry I'm getting back to you late. I'm with the others though, I think it's an ignition problem. One thing I KNOW works well for me is replacing the plug wire, boot, and cap to better material I always go to napa and get better. Also, are you running the stock plug? NGK is the best :) Norm's idea about it not grounding sounds like a really good one, also, BE SURE your mag rotor is on the right way, you didn't say whether you checked that or not. Lastly, I love this little device right here 90§ Inline Ignition Spark Checker Makes checking the spark a breeze, it will flicker orange if you are getting anything. Hope this helps. Good luck man :)
-LS
 
Make sure you have the key inserted on the mag rotor shaft and that the rotor is on correctly. Super gluing the darn key is about the only easy way to keep it in place. I can't tell in one of your photos if the ground wire is attached to one of the magneto's frame mounting bolts?
Did you check the first engine to see if the mag rotor's key sheared? that will stop the engine dead.
 
kind of a blurry picture but its kinda hard getting a photo of a guy goin by at 25 mph! lol
 

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OK.. Sooo..
what I had was 2 motors, 4 cdi's and a very cheap volt meter! After borrowing a volt meter from a neighbor I found 2 of the cdi"s to be bad and a ground wire in the mag that had a worn spot in the wire sheathing. Sitting on the stand "still" the wires all checked out per chart found on another link. As I would attempt to look for spark the wire obviously was rubbing against something inside the casting. After pulling the magneto i realized this and fixed the wire. BANG full strong spark. Stll can not get mag to check out properly in motor #1 with volt meter but I now have a couple weeks of riding to make up for so that will be a bench project for another day. I believe that this was a combination of having way to many parts swapping in and out of the 2 motors in a hurry and me just not slowing down enough to really think thru the issue. I just never hit the correct combo of good parts. Thank you for all of the insight guys!

Norm- I did reinstall the mag with the ground wire connected by the mag mounting screws. Is this not the correct or best way?
 
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