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Discussion Starter #1
Hello,
Nice forum you have here. I just got back on a bike after many years of wasting my time. I picked up a 78 CB400T for $200. New coils, clean carbs and fresh oil got her back on the road humming nicely.
Then after several hundred miles I went to warm it up one cool morning. It started fine, and then quit. The engine seized. The starter won't crank. The kick starter won't budge. I can't roll the bike in fourth gear. But I can rotate the pistons with a wrench. I removed the top and all valves move correctly. I peaked under the right case and nothing looks out of the ordinary. I suspect I have to split the cases but do any of you wrenches have a guess as to what I am looking for? This will be my first time inside the guts of an engine.
Thanks, David
 

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Have you tried any of this with the bike on the center stand?

Just how do you 'rotate the pistons with a wrench'? Did you remove the stator cover and turn the rotor?

If that is how you do it, then the motor isn't seized. And, since the starter motor directly turns the rotor, that's a different problem. The kick starter turns the input shaft of the transmission, which then turns the engine through the clutch via the primary gears. You could have two gears engaged at the same time, or just stuck in gear if the wheel is down (shift fork failure), or the kickstart could be jammed. Taking the right engine cover off will reveal the kickstart; much of it is behind the clutch, but you could still see how it is working. The transmission requires turning the engine upside-down, and taking the bottom off the engine; not difficult, just keep track of which bolt goes where, as they are probably not all the same size/length.
 

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Discussion Starter #3
The bike is on the center stand and I can shift through the gears. I removed the stator cover and turned the rotor. So it appears the kick starter might be the problem. I couldn't see any problems when I peaked behind the clutch, but there is some play in the kick starter, both in and out and some wiggle, but that might be because cover is off. What would cause that to happen?
 

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With the bike in neutral,pull the clutch and see if the kickstart 'freewheels'.

Also check the clutch cable to make sure that it engages and releases the clutch
 
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