rear wheel spins without any throttle...

D

Damian84

New Member
so I have the GT5 grubee with the NT carb. I have the SBP shift kit. when i start pedaling it fires up and seems like it wants to go when i give it a little throttle. but then dies... so i put it up on a rear axle stand to troubleshoot. I kicked down on the pedal and it started right up!! idle was good with cluch engaged and dis-engaged. And i always get them confused with which position the clutch lever is engaged and disengaged. So with the clutch lever released.... my back tire would spin at a low speed. when i tried to force it to stop, the motor would die.

1. Why is my back tire spinning with no throttle?

everything seems to be running great when the rear tire is off the ground...

2. So why when i get it moving forward it dies with a little throttle?

Float position is good. idle is perfect. fires easily, thus the kick start...

Im soo lost...

Any ideas
 
Well, your wheel should spin with the clutch released (engaged) and it should kill the engine when you try to stop it with the clutch engaged.

As for why the engine dies when you give it throttle, it could be anything from too slow of an engine speed, to a slightly lean condition.
 
ok. i know how to adjust the lean/rich condition i think i.e. gas/oil ratio or needle setting or float level.... but, how would one adjust the engine speed?
 
There is a throttle speed adjustment on the side of the Carb... its usually a screw with a Phillips head with a spring behind it.
Lets adjust the idel speed

And its like driving a stick shift, you gotta give it some gas from a dead stop until engine rpm and wheel speed start to match up... if not its gonna stall or be all jerky
 
Damian84 said:
so I have the GT5 grubee with the NT carb. I have the SBP shift kit. when i start pedaling it fires up and seems like it wants to go when i give it a little throttle. but then dies... so i put it up on a rear axle stand to troubleshoot. I kicked down on the pedal and it started right up!! idle was good with cluch engaged and dis-engaged. And i always get them confused with which position the clutch lever is engaged and disengaged. So with the clutch lever released.... my back tire would spin at a low speed. when i tried to force it to stop, the motor would die.

1. Why is my back tire spinning with no throttle?

everything seems to be running great when the rear tire is off the ground...

2. So why when i get it moving forward it dies with a little throttle?

Float position is good. idle is perfect. fires easily, thus the kick start...

Im soo lost...

Any ideas
Click to expand...

With the clutch handle fully released the motor chain is engaged and the rear wheel is supposed to be spinning, if you force it to stop spinning the motor should die (it has to).

As far as it stalling when you twist the throttle, could be lots of things. I kinda think you are just not going about it properly. These are pedal assist kits, they are not designed to pull you from a dead stop, you have to be rolling first. So get the bike rolling at least a couple MPH, and then rev the throttle a little bit as you slowly release the clutch (as you would with a motorcycle or stick shift car) and I bet you will get going. If you have the bike running on a stand (rear wheel spinning) you should be able to pull in and lock the clutch lever, at this point you should be able to stop the rear wheel without killing the motor if your clutch is adjusted properly. With the clutch locked in you should be able to rev the motor above idle by twisting the throttle. If you do this and she dies than you do have some sort of problem....
 
One thing we older guys have to keep in mind is that there is a whole generation, maybe two, out there who have never driven a vehicle with a manual transmission. It's the same as asking them how to change TV channels without a remote.

Try to recall what your first experience was with using a clutch. Same thing for our younger/newer members.

The challenge for them is compounded with a 2 stroke in-frame engine because they aren't designed to pull away from a dead stop. Now we have to add pedaling up to speed and getting a 'feel' for how to use a clutch.

Tom
 
I'm only 20, when I first started driving I insisted on learning how to drive a stick shift before automatic
But yea I seen customer builds were a Guy has never drove a stick shift. Much less he has never pulled a spark plug. Lets just say he wasn't the sharpest tool in the shed lol
 
ocho ninja said:
I'm only 20, when I first started driving I insisted on learning how to drive a stick shift before automatic
But yea I seen customer builds were a Guy has never drove a stick shift. Much less he has never pulled a spark plug. Lets just say he wasn't the sharpest tool in the shed lol
Click to expand...

My personal favorite was a woman who FILLED her car engine with oil. Didn't use the dipstick, just kept dumping it in until she could see it in the valvecover opening.
Wondered why it would not turn over this way.
Came to me to help her get it started again.
After I got done laughing and pointing at her, I drained the oil, explained her mistake and sent her on her way.
Scared me to death to think this woman was behind the wheel of a car.
 
I saw a friend do that once... came over to my house all happy that he did his first solo oil change. He got to my house absolutely terrified that his engine was toast because he there was smoke everywhere, its beacause he topped of the oil to the brim of the filler
 
To start from a dead stop with the engine idling, you'd probably have to be a master with the clutch.
When you keep the clutch engaged (tensioned, no rear wheel movement), and roll open the throttle, does the engine rev, or die?
 
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