4 stroke with gearbox.

[michael whiteman]

OK guys........let's get back on track here. ALL engines that we use rotate the same direction. ALL gearbox output shafts rotate the same direction. ALL chains and wheels turn the same direction.

I was under the impression 11T freewheel sprockets did not come on the dual chain transmission. If you were to put it on the shaft backwards the chain would not align with the wheel sprocket and it would just ratchet with no forward movement.

Now, if the bike won't idle without the tire trying to spin, then the clutch is NOT disengaging. Take the cover and/or the transmission off and check it out. The clutch bell needs to turn freely with the engine turned off. A freewheel might make this more difficult to test.

I am sure this is a tapered shaft engine. If it was a straight shaft engine, which I am sure it is not, it would have a bolt through the clutch bell in the end of the crankshaft. On a straight shaft engine there is always the likelihood that the bushing in the clutch bell is sticking to the crankshaft not allowing it to spin freely when the engine is off. This will create the scenario you are experiencing. Many of us with belt drive transmissions have encountered this.

 

[Karl Snarl]

OK guys........let's get back on track here. ALL engines that we use rotate the same direction. ALL gearbox output shafts rotate the same direction. ALL chains and wheels turn the same direction.

I was under the impression 11T freewheel sprockets did not come on the dual chain transmission. If you were to put it on the shaft backwards the chain would not align with the wheel sprocket and it would just ratchet with no forward movement.

Now, if the bike won't idle without the tire trying to spin, then the clutch is NOT disengaging. Take the cover and/or the transmission off and check it out. The clutch bell needs to turn freely with the engine turned off. A freewheel might make this more difficult to test.

I am sure this is a tapered shaft engine. If it was a straight shaft engine, which I am sure it is not, it would have a bolt through the clutch bell in the end of the crankshaft. On a straight shaft engine there is always the likelihood that the bushing in the clutch bell is sticking to the crankshaft not allowing it to spin freely when the engine is off. This will create the scenario you are experiencing. Many of us with belt drive transmissions have encountered this.

Not all engine do rotate in the same direction. The HT all rotate backwards, so do all my pocket bike engines, etc. My 4 strokes rotate the other way, lol. 2 stroke has gear reduction and reversal, 4 stroke has chains and belts, and I think they may have a gear box, but Idk, I use mainly 2 strokes.

 

[michael whiteman]

Karl......did you read there where I said "all the engines that we use" I'm talking about 2 and 4 cycle motors that most all of us are using on our motorized bicycles. Not "pocket bikes" and all the other odd ball engines. And who cares how many gears are in a transmission or which way they rotate because the output shaft direction is all that matters. I realize you're a pretty knowledgeable fellow regarding this sport and I'm sure there are a few of the followers that are getting some amusement with the two of us going back and forth. To these long time members this forum is a place to hang out with the rest of their friends and offer up a few ideas from time to time. The people who, I believe, benefit the most are the younger new comers who don't have the mechanical experience that we do and are asking themselves "what have I gotten into here?" as they open their box of parts that is hopefully going to become a motorized bike. With all the experience I have had in my life building custom race cars this recent adventure building my rat bike has been very challenging. We all need to share our experiences in a way newbies can understand as simply as possible. I am very thankful for all the insight that has been given to me by the members of this forum. Sincerely.

 

[Jjcds79]

Karl......did you read there where I said "all the engines that we use" I'm talking about 2 and 4 cycle motors that most all of us are using on our motorized bicycles. Not "pocket bikes" and all the other odd ball engines. And who cares how many gears are in a transmission or which way they rotate because the output shaft direction is all that matters. I realize you're a pretty knowledgeable fellow regarding this sport and I'm sure there are a few of the followers that are getting some amusement with the two of us going back and forth. To these long time members this forum is a place to hang out with the rest of their friends and offer up a few ideas from time to time. The people who, I believe, benefit the most are the younger new comers who don't have the mechanical experience that we do and are asking themselves "what have I gotten into here?" as they open their box of parts that is hopefully going to become a motorized bike. With all the experience I have had in my life building custom race cars this recent adventure building my rat bike has been very challenging. We all need to share our experiences in a way newbies can understand as simply as possible. I am very thankful for all the insight that has been given to me by the members of this forum. Sincerely.

I am a newbie to motorized bikes and motors in general but at 40 years old i have taken in love with it. Knowledge is power and ignorance cost me in parts. But like anything you can't learn without mistakes. I appreciate any and all info thank you guys bunches for taking the time to reply and offer up your expertise.

 

[Sidewinder Jerry]

I am a newbie to motorized bikes and motors in general but at 40 years old i have taken in love with it. Knowledge is power and ignorance cost me in parts. But like anything you can't learn without mistakes. I appreciate any and all info thank you guys bunches for taking the time to reply and offer up your expertise.

Here's a philosophy I often share:

We're all born ignorant.

Idiots never learn from their mistakes.

The intelligent learn from their mistakes.

The truly wise learns from their mistakes of others.

 

[Wrench]

I am a newbie to motorized bikes and motors in general but at 40 years old i have taken in love with it. Knowledge is power and ignorance cost me in parts. But like anything you can't learn without mistakes. I appreciate any and all info thank you guys bunches for taking the time to reply and offer up your expertise.

So, with the suggestions members have given you have ya figured out what's wrong?

 

[Will'smotobikes19]

I have the same gearbox it allows to travel one way but not the other. I'd just adjust the idle speed.

 

[nevin]

idle may be high, and would keep the clutch engaged and constantly pulling you forward.

you could also have a stuck clutch. on the 4strokes, it's mounted to the output shaft of the motor
like this.

and the "bell" of the clutch (in gold below) is what the pads contact with.
so if you unbolt the gearbox, the clutch will be right there.

as the motor spins faster, the weighted pads move out contacting the bell and moving the chain & the bike forward.
when you let off the throttle, the lack of spinning movement and the springs help pull the pads back in away from the bell, no more contact with the bell, not driving the chain until you give it gas again and the clutch engages (pads contact the bell & start spinning the chain)

 

[Sidewinder Jerry]

idle may be high, and would keep the clutch engaged and constantly pulling you forward.

you could also have a stuck clutch. on the 4strokes, it's mounted to the output shaft of the motor
like this.
View attachment 157403
and the "bell" of the clutch (in gold below) is what the pads contact with.
so if you unbolt the gearbox, the clutch will be right there.
View attachment 157404
as the motor spins faster, the weighted pads move out contacting the bell and moving the chain & the bike forward.
when you let off the throttle, the lack of spinning movement and the springs help pull the pads back in away from the bell, no more contact with the bell, not driving the chain until you give it gas again and the clutch engages (pads contact the bell & start spinning the chain)

That's a reduction chain drive transmission. A gearbox has gears inside of them.

 

[nevin]

Look at the pic op posted. This is what he has. A reduction box.