Frozen sprocket

M

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Ive put roughly 1,000 miles on my 7 speed beach cruiser since I install a 49cc motor. I tightened the chain tension because the chain is stretching, became loose where chain was falling off back tire sprocket when going fast over bumpier terrain..
Anyways.. With clutch engaged I can move bike freely but back wheel wont even move when clutch disengaged. Normally I would hear engine compression as I rode it as if no gas...but since the back wheel won't move I'm not sure if it's the drivetrain issue inside the engine behind the sprocket. I've opened cover. Just real greasy and appears to have metal shavings... What might I need to replace? I already ordered new chain and tensioner.
Please help... I put 20 miles a day on it...usually.
P.s. the chain isn't bunched up around the sprocket, as I said it moves when the clutch is engaged but when the clutch is not engaged it doesn't do anything except freeze.
Would the magneto have anything to do with this?
 


crassius

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Jul 23, 2012
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clutch not engaged is when the chain should move without turning motor - you have that backwards

if chain and front sprocket and clutch hub all turn when clutch is not engaged, but engaging clutch stops everything, then motor may be seized or some piece of metal got stuck in teeth of the bevel gears - first, take out spark plug and try to turn motor by putting a wrench on nut on rotor

if motor won't turn, take off clutch cover and see if anything is stuck in gear teeth
 

Will'smotobikes19

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Something could be seized or the woodruff key the stator stays in the same place whether or not the clutch is engaged. Check the teeth on the gears they might have worn away some.
 
M

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clutch not engaged is when the chain should move without turning motor - you have that backwards

if chain and front sprocket and clutch hub all turn when clutch is not engaged, but engaging clutch stops everything, then motor may be seized or some piece of metal got stuck in teeth of the bevel gears - first, take out spark plug and try to turn motor by putting a wrench on nut on rotor

if motor won't turn, take off clutch cover and see if anything is stuck in gear teeth
The cover, over the sprocket where the chain goes, had what appeared to me were metal threads that had came off as shavings with a whole bunch of grease and dirt, so I cleaned it and put it back on... when I pull the lever for the clutch the bike moves, but when I release the lever for the clutch my bike won't move. Unless I lift up the back wheel.
All I did was I couldn't afford the chain tensioner and a new chain right away so I took the hole chain bracket tensioner off and I tighten it by hand and then I put it back on, the Chain had enough play in it but as soon as I started the motor it ran for a minute and then it locked up.
I haven't tried the spark plug yet but what is exactly the crank connected to and could that have broke.?
 
M

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Something could be seized or the woodruff key the stator stays in the same place whether or not the clutch is engaged. Check the teeth on the gears they might have worn away some.
Everything looks normal to me but I don't know Motors, and I'm wondering if whatever the sprocket crank is attached to if that broke somehow and that's what's causing the back wheel to seize because the motor is not even turning over, I can't even pedal the bike without pulling the lever for the clutch.
 

Will'smotobikes19

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Everything looks normal to me but I don't know Motors, and I'm wondering if whatever the sprocket crank is attached to if that broke somehow and that's what's causing the back wheel to seize because the motor is not even turning over, I can't even pedal the bike without pulling the lever for the clutch.
You might have seized it or overheated the engine, take the head off and look in there. The clutch shaft could have seized.
 

Frankenstein

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Jun 24, 2016
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You might have seized it or overheated the engine, take the head off and look in there. The clutch shaft could have seized.
The clutch is not seized as that is always connected to the wheel, even when clutch is pulled.

His motor probably just took a dive, but a small chance the gears have stuff in them, usually you can roll it backwards a tad if it's the teeth since that's just how gears work. 1000 miles isn't bad, actually a pretty good average for these motors, I bet his wrist pin bearing turned into those magic sprinkles we all like.
 
M

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The clutch is not seized as that is always connected to the wheel, even when clutch is pulled.

His motor probably just took a dive, but a small chance the gears have stuff in them, usually you can roll it backwards a tad if it's the teeth since that's just how gears work. 1000 miles isn't bad, actually a pretty good average for these motors, I bet his wrist pin bearing turned into those magic sprinkles we all like.
How many miles does a 49cc motor go? It's odd for me to believe that it was running fine and all I did was adjust the chain tensioner and then itseized, what actually seized is a question?
I think it actually has something to do maybe I pushed the rod I don't know to the piston?
Everything worked fine and great until I adjust to the tension rod and that's weird the back Wheels stopped moving when the clutch was disengaged if I'm saying that right when I pulled the lever that's the only time it will roll.
Baby when I need to do is look at the piston and self but like I said before I think it has something to do with the crank sprocket connected to the engine.
 

Will'smotobikes19

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Like even if you pull the wheel hard? The clutch plate moves off the pads when you pull the lever. Take the cover off and look at your clutch. You might need to adjust your flower nut or your clutch cable.
 
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