Hard/Impossible to turn chain sprocket on new motor by hand ??

SloRyd

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So i'm in the process of building my first M/B. I've been wrenching on dirt bikes and Harleys for 40 years or so....I mounted the motor, removed the arm side cover and tried turning the sprocket by hand....couldn't budge it.

Thought...ahhhh, the clutch is engaged and it's trying to turn over the motor even though the spark plug isn't installed. Install the clutch cable and lever, fully depress the clutch lever and lock it with the pin, still no go...won't budge. So then I pop off the clutch side cover, remove the star wheel and pressure plate exposing the friction disc pads to get a sense of how it all works, still very hard to turn it by hand, I put a 3/8" socket adapter on my drill, 15mm socket on the center shaft nut and turned it over that way.....spun it for 30 seconds or so to see if it was just factory tight and just needed to be worked a little....but it's still damn near impossible to turn the sprocket side by hand. I put the pressure plate and star wheel back on and buttoned it up.

I'm thinking that when I go to pedal to start this thing...there's going to be significant drag on the chain/sprocket assembly and that it shouldn't have that much resistance. Can you free spin your sprocket by hand or spin the back wheel easily with the lever pulled in for those that have finished daily rider bikes?? Something doesn't seem right to me for it to be that tight from the factory. It'd probably be pretty difficult to push this thing when it's all together without any weight on the back tire....it might just skid along standing next to the bike. I guess I'll find out tonight once I mound the sprocket and connect the chain??? Anyone have this issue when new?? Do the bearings have to free up on the motor jackshaft when new (which doesn't seem logical) ??
 

Street Ryderz

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Yeah they can be tight at first, sometimes even stuck! The bearings and grease dry up in the clutch base plate and some times the shaft bearings are not square.Easily corrected then yes it should spin nicely!
 

Chainlube

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Use a socket on the sprocket to turn it and install your chain. This might loosen the mechanism too.
 

SloRyd

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Use a socket on the sprocket to turn it and install your chain. This might loosen the mechanism too.
I spun it for a good 30-45 seconds with a drill mounted socket...still tight afterwards. Weird but hopefully everything will work loose once it’s running and gets ridden a little.
 
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