wheel wont spin

GoldenMotor.com
Jan 12, 2015
125
0
16
Merced, California
my friends and I have been working on putting together our first motorized bike this weekend and we have run into a problem that we can't figure out. I thought I should come here to consult with the masters. So after we instaled the drive chain, something locked up and now the wheel won't turn anymore. we think that maybe the chain is hitting something inside the motor wrong and causing it to lock up. has anyone had this problem before or know what a possible solution could be?
 

bluegoatwoods

Active Member
Jul 29, 2012
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Yes. There can be a handful of causes for this. And the 'feeling' you're getting points to one possible cause; your engine chain binding up under the output shaft cover.

You can have a look by pulling that cover off. You can turn your output shaft using a socket (about 15 mm, if I remember right) or using the spark plug 'wrench' that came with the kit.

By the way, take the spark plug out for easy engine turning.

DSCN0409.JPG
 
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2door

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Sep 15, 2008
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Littleton, Colorado
Can you move the wheel when the clutch is engaged or will it not move whether or not it is engaged or disengaged?
Good question and one that will tell you if it is a chain bind problem or if the clutch cable isn't adjusted correctly. If the cable is too loose the clutch is staying engaged even with the handlebar lever squeezed.

If the rear wheel binds even with the clutch disengaged (assuming the cable is right) then the chain is probably binding on the drive sprocket. This happens when the chain is too loose or chain/sprocket alignment is way off.

Tom
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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Also remove the front sprocket cover and look for marks where the chain is rubbing. Some new motors need a bit of grinding under the cover for chain clearance.
Check for chain alignment causing the chain to come off the side of the sprocket and bind.
 

MotorBicycleRacing

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Jul 28, 2010
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my friends and I have been working on putting together our first motorized bike this weekend and we have run into a problem that we can't figure out. I thought I should come here to consult with the masters. So after we instaled the drive chain, something locked up and now the wheel won't turn anymore. we think that maybe the chain is hitting something inside the motor wrong and causing it to lock up. has anyone had this problem before or know what a possible solution could be?
New motors come out of the box with the clutch 'stuck"
I have to break the clutch free on every new motor.

Pull the clutch lever in.

Lift rear wheel off the ground and give it a quick and sudden turn to break the clutch loose.

You may have to repeat a few times.

You can also pull the clutch lever in and roll the bike.

I break them free with the motor on it's side on the bench using a straight screw driver to flick the 10 tooth sprocket using the motor housing as a fulcrum.
 
Jan 12, 2015
125
0
16
Merced, California
Update: we didnt completely solve the problem but progress has been made. the chain had buckled underneath the three bolt cover and that was stopping it from turning. as of now, the wheel does turn but it is extremely clunky. i may try to see if the chain is rubbing they way MotorBicycleRacing suggests.
 

MotorBicycleRacing

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Jul 28, 2010
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If you are using a 415 chain the chain will rub inside the front of the 3 bolt sprocket cover.

You can file away a small piece of the cover so the chain does not have to.

however this is not your problem with the back wheel locking up after you install the chain.
 

fatdaddy

New Member
May 4, 2011
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San Jose, Ca.
Did the motor and chain come together in a kit? Or did ya get them separatly?
The wrong size chain will chunk and clunk forever and never be right.
fatdaddy.
 

2door

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Sep 15, 2008
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My suspicion is the clutch cable is either not installed yet or not adjusted correctly.

When you squeeze the handlebar lever the rear wheel should spin free. Tell us how you adjusted the clutch cable.
Here is a good tutorial for adjusting the clutch. Just make sure the cable is correct before you start messing with the internal clutch parts. http://motorbicycling.com/showthread.php?t=22726

Tom
 
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fatdaddy

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May 4, 2011
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My suspicion is the clutch cable is either not installed yet or not adjusted correctly.

When you squeeze the handlebar lever the rear wheel should spin free. Tell us how you adjusted the clutch cable.
Here is a good tutorial for adjusting the clutch. Just make sure the cable is correct before you start messing with the internal clutch parts. http://motorbicycling.com/showthread.php?t=22726

Tom
Hey Tom, The guy says its turning, Just real clunky. Sounds to me more like something aint lined up right or the wrong size chain. I've had chain that fits one drive sprocket just fine, But just wants to chunk and clunk on another. I blame it on the difference's between the 10 or so manufacturers.
fatdaddy.
 
Jan 12, 2015
125
0
16
Merced, California
ok so i took the chain off and still the output sprocket or whatever its called turns clunkily so its not the chain rubbing against the housing. i tried to take a video of what i mean but my phone recorded in in an invalid format. the chain came with the kit so i would hope they had the decency to give me the right size. on another note does anyone know any tricks to bending the exhaust pipe? its just ever so slightly in the way of the pedals and theres no way i can do it by hand.
zpt
 

fatdaddy

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May 4, 2011
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The drive gear should not turn clunky, I have no idea why it would. Try to find out where its binding. As for the pipe, If all ya got is the peddle arm ticking on it sometimes you can put it in a vice and bend it back just a little where the pipe is welded to the muffler part, JUST A LITTLE or the weld will break. Sometimes all ya need is a little. Also, Theres always a little play where it bolts up. try loosening the nuts and holding it over while you tighten it back up. Sometimes all ya need is a little.
fatdaddy.
 

2door

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Sep 15, 2008
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Try removing the spark plug and see if the "clunky" goes away. Without the clutch actuator disengaging the clutch the drive sprocket will have resistance when the piston comes up against compression. That will happen once every crankshaft rotation.

I still say your problem is the clutch cable not adjusted correctly, or not installed.
Did you read the tutorial I provided on how to adjust the clutch cable? Did you try what was suggested by Motorbicycleracing as far as freeing up a stuck clutch?

Tom
 

maniac57

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Oct 8, 2011
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As far as your pipe hitting the pedals, the easiest way to fix it is to drill the holes in the exhaust pipe one size bigger. This allows you to rotate the pipe a bit and almost always gives enough clearance to fit.
Just don't go hog wild. One or MAYBE two sizes gives you plenty of movement.
 

2door

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Sep 15, 2008
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Littleton, Colorado
As far as your pipe hitting the pedals, the easiest way to fix it is to drill the holes in the exhaust pipe one size bigger. This allows you to rotate the pipe a bit and almost always gives enough clearance to fit.
Just don't go hog wild. One or MAYBE two sizes gives you plenty of movement.
If this doesn't work then clamp the flange in a vice and 'cold bend' the pipe. There is no reason to heat it. The pipe will bend without heat but you need to take it easy and go slow so you don't over bend it. However, enlarging the holes will usually give you the clearance you need. Good luck.

Tom
 
Jan 12, 2015
125
0
16
Merced, California
i have the three bolt cover that goes over the ten tooth gear removed right now and the clutch arm is on that so it cant be that the clutch is stuck. as for how i have the clutch adjusted the arm is parallel to the smooth side of the motor. sorry if im being a little frustrating with this whole thing, i really have no experience or knowledge with these kinds of things.
 

2door

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Sep 15, 2008
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Littleton, Colorado
i have the three bolt cover that goes over the ten tooth gear removed right now and the clutch arm is on that so it cant be that the clutch is stuck. as for how i have the clutch adjusted the arm is parallel to the smooth side of the motor. sorry if im being a little frustrating with this whole thing, i really have no experience or knowledge with these kinds of things.
With that cover removed the clutch will be engaged. The sprocket won't turn easily unless you remove the spark plug. That cover is part of the clutch actuating system. The cam inside it pushes against a steel pin, called a 'bucking bar' which in turn presses against a ball bearing that rides against another moving part inside that when moved releases the spring pressure and disengages the clutch. If that cover is not on and the cable not installed it will be difficult to rotate the drive sprocket and if the chain is installed the rear wheel won't turn easily.

How did you install the chain the first time without rotating the drive sprocket?
Could you post some photos to help us determine what you have currently?

Tom
 

fatdaddy

New Member
May 4, 2011
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San Jose, Ca.
As long as ya got the cover off, take out the bucking bar, (pin) and shove some good bearing grease in the hole. Replacing the "pin" will push it where it needs to go. (Wipe off excess) Be carefull not to lose the bearing inside. with no grease to hold it in, it may just roll out. Is there a member that lives nearby that could help you out? If you were anywhere near me I'd be glad to take a look for ya.
fatdaddy.
 
Jan 12, 2015
125
0
16
Merced, California
so just now i tried turning it with the clutch lever pulled in in case it was a maladjusted clutch cable like 2door suggested. sorry fatdaddy i had already put the cover on before i checked the website and saw your most recent post tonight. i thought i had the clutch adjusted correctly because the clutch arm was lined up parallel like the tutorials and instructions say to, but then i tried to really squeeze the **** out of the lever it began turning a little more smoothly and i could even pedal a little. but i had squeeze super hard and it was very uncomfortable so i guess i need to tighten up the cable down where the clutch arm is. I'll try that and then get back to all of you
 
Jan 12, 2015
125
0
16
Merced, California
ok i tightened up the cable and the lever is really hard to pull now. the wheel still loosens up when i pull the lever but its super tight. i know im not the strongest guy around but i dont think i should have to give it all ive got just to pull the clutch lever