Backfiring and now not running

L

leadfarmer

New Member
A couple of weeks ago my china girl engine, after running fine all day, stopped idling and then quit running altogether.
I put in a new NGK B5 plug today, it was hard to start, but ran for a couple of miles. I had to keep the RPM's high or it would die. Then it quit and will not run at all. The plug is wet and I suspect a fuel issue as it seems to have spark and copression. By the way I tried a different CDI, no luck.
While it was running, it was backfiring through the exhaust and carberator.
Any ideas how to get it purring again?
 
Check the Woodruff key that is used to hold the magnet in position on the crankshaft.
Could be missing, causing the magnet to shift position on the crankshaft, causing hard starts, backfiring, etc.
 
The easiest thing to do is to check to see if the magnet is in the right position.
First rotate the engine so that the piston is at the top of its stroke. If you have a strong light, you can probably see this thru the spark plug hole.
At this point the flats of the magnet should be at the top and bottom, and the keyway will be at 1 o' clock. You will probably need to remove the nut in order to see the keyway.

Magnet flats top and bottom:


Keyway at 1 o' clock:
 
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My magnet is in the correct position and the woodruff key is intact. I don't have a spark. I think I disconnected the killswitch(unplugged the wires) and nothing. I am going to buy a new magneto next.
 
If you have a multimeter, you can check the resistance of the magneto coils to see if they are within specs.
 
leadfarmer said:
The new magneto fixed the problem. My bike runs again!
Click to expand...
Good for you and thank you for letting us know. We always like to hear back from a member when he has a problem and resolves it. Thanks again.
Have fun, ride safe.
Tom
 
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