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Discussion Starter #1 (Edited)
I know you guys are pitbike dudes but this is the same engine and I need help. I was doing a replacement top end and I think everything went perfectly. Put it back on my C70 passport and I heard my baby purr for the first time. It sounded great. I was doing some carb adjustment and. SNAP. It died. I can still kick the bike freely but kicking it doesn't move the Piston. It also doesn't move the chain that is around the magneto thing on the left side of the engine. Here is a video if it helps. My only thought would be that the connecting rod broke but I had just put brand new oil in it. All the way to the top of the dip stick. I just don't know what happened! Any help is much much appreciated. Thank you in advance.


BIG IMPORTANT UPDATE. THE PISTON IS MOVING AND INTACT. THE TIMING CHAIN IS MOVING AND INTACT. THE VALVES ARE FROZEN EVEN THOUGH THE TIMING GEAR IS TURNING.
 

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Not able to see your video for some reason, but if the kicker does not engage the crankshaft, it is in the clutch. Your clutch could have dropped the c-clip that holds the plates in or the clutch nut is loose. The other possibility is that the clutch adjuster is turned too far (counterclockwise.)
 

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Discussion Starter #3
Not able to see your video for some reason, but if the kicker does not engage the crankshaft, it is in the clutch. Your clutch could have dropped the c-clip that holds the plates in or the clutch nut is loose. The other possibility is that the clutch adjuster is turned too far (counterclockwise.)
Ok. Thanks so much for your reply. Would the big magneto thing still move tho? Also. Do you have a video to help me adjust that? I'm new to these engines. I do have the service menu too. I'll check that as well.
 

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The kickstarter is turning the engine over in the video, the starter motor and chain is not moving because he is using the kickstarter, dave. He is also getting "thumb resistance" compression while kicking it over, so the con rod isn't broken.
 

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I can see your vid. The chain you're seeing...not move, is part of a electric starter, I think. But your flywheel is spinning. That would indicate that the crankshaft is spinning. If the piston is not moving...but the crank is spinning...something is way wrong. I'm not familiar with this c70 engine...but...the piston connects to the rod connects to the crank connects to the flywheel...
 

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Did you reset the carb back to the settings it had before you started adjusting it, and try to start it?
 

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Discussion Starter #7
The kickstarter is turning the engine over in the video, the starter motor and chain is not moving because he is using the kickstarter, dave. He is also getting "thumb resistance" compression while kicking it over, so the con rod isn't broken.
I just don't understand where the compression is coming from if the Piston isn't moving?
 

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Logically thinking, the piston has to be moving to create the compression, take a drinking straw and stick it down in the spark plug hole and then turn the flywheel (magneto) counterclockwise by hand and see if the straw goes up and down.
 

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Is it an '80-'81 or an '82-'83?

Do you get spark at the plug by holding it to a bolt on the head and having someone kick it over?
 

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Looking at the vid again...that could be the intake valve that I see in the spark plug hole. Is your intake valve stuck open.. piston moving but the valve stuck??
 

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Discussion Starter #12
Looking at the vid again...that could be the intake valve that I see in the spark plug hole. Is your intake valve stuck open.. piston moving but the valve stuck??
OH SH!T YOU ARE BRILLIANT. I think this might be it!! I'll check when I get home!!! How can I go about fixing that? MAYBE THAT LITTLE CHAIN BROKE. The one that runs along the right side of the engine and times the valves. THAT DEFINITELY could have been the pop. Sorry for all the caps but I thought this engine was dead dead. You have given me new found hope!!!
 

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OH SH!T YOU ARE BRILLIANT. I think this might be it!! I'll check when I get home!!! How can I go about fixing that? MAYBE THAT LITTLE CHAIN BROKE. The one that runs along the right side of the engine and times the valves. THAT DEFINITELY could have been the pop. Sorry for all the caps but I thought this engine was dead dead. You have given me new found hope!!!

Remember how I told you to check the cam chain (we talked on Reddit and I convinced him to join PM)...that's the cam chain I was talking about. I'm guessing you were thinking about the chain for your e-start.
 
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