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Discussion Starter #1
Ok if this sounds dumb forgive me but I never noticed this before. I just finished replacing the cases on my 93/900SS after they cracked in half on me. I replaced them and put engine back together. Crank pre-load and gear-shaft end-float all set to perfection, crank would spin by hand with almost no resistance once cases were torqued together. Once together I also checked run-out on crank, reading was practically null. Since I was waiting on new 944 Cyl to show up I put side covers on to keep crap out. When I rotate engine now I have resistance, engine will turn easy maybe a half a nat ass have big resistance, release, move another half a nat ass resistance again. Pulled stator cover, everything is fine engine rotates free. Pulled bearing out of cover, replace with another I had, put back on, same issue. From what I see, resistance is coming from the rotor/stator, as they pass each other the magnets cause this resistance.

My ? is this a problem? I only ask as I cannot get bike to run above Idle right now and I'm going through a process of elimination, and since I have have never seen this before I have to ask.

BTW I have a 750 motor sitting in the garage and from what I can tell I do not have this resistance.

Thanks in advance
 

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Retired Pipe Polisher C2H6O+
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Gee Tye. Even with the cylinders off?
 

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Discussion Starter #4
Its a 4 stroke motor... one of the strokes is a "compression" stroke, which builds up compression before igniting the fuel. So yea, if you turn the motor over by hand, you'll find it hard to turn.

Sounds pretty normal to me.
Boy glad you set me straight on that...must have missed day 1 of engine 101.......As I said it was doing this without the Cyl or pistons installed, after changing the bearing in the side cover and checking run-out I figured this was probably normal and finished building engine. Now I'm having an issue getting bike to run above Idle so I'm just going through a process of elimination and this was the only part during the build that struck me a "odd"
 

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How does he ".... get it to run at idle" with the cylinders off?

Anyway, the stator magnet is pretty strong and will offer some resistance when the magnetic poles align.

Did you remove the stator from the case during the rebuild? If it's not seated squarely in the case, it may rub on the magnet, but that would a constant source of friction, not intermittent.
 

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Chilehead
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Anyway, the stator magnet is pretty strong and will offer some resistance when the magnetic poles align
Um, the stator has no magnets, the rotor does. The stator is just a series of coils.

And what would they align with?

Sorry, just doesn't happen with an alternator.

Tom
 

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Yeah the crankshaft should move smoothly without binding. The mangets will not affect it; you can turn a car alternator just fine. Even with the heads on with full compression you can turn the engine over smoothly. Sounds like there is something binding up the crankshaft on that stator side cover. Something is out of line / bent / rubbing.
 

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How does he ".... get it to run at idle" with the cylinders off?

Anyway, the stator magnet is pretty strong and will offer some resistance when the magnetic poles align.

Did you remove the stator from the case during the rebuild? If it's not seated squarely in the case, it may rub on the magnet, but that would a constant source of friction, not intermittent.
This is not possible, the magnet causes the coils to have magnetics poles. Hence, you can't get 2 of the same poles together... ever...
 

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Well, duh, I stand corrected. Sorry for the confusion.
 
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