Weird throttle response

[NicoMec]

So I have been running into this issue lately and I have not been able to figure out what's been going on. I figured it would be best to upload a video instead of me trying to explain it. But for context as you can see in the video, The bike was running/idling just fine and revving fine as well. Put the choke down and revved it again and then all of a sudden RPMs dropped and when I tried to rev it towards the end it almost sounds delayed and struggled to rev. It's gotten to the point where the RPMs drop so much that the engine just eventually dies out. (Apologies for the bad video and audio quality, it was recorded with a fake $30 GoPro)

 

[ImpulseRocket]

Choke on, fueling fine. Choke off, fueling not fine. You answered your own question. It's lean enough to stall out with the Choke off. Choke on and it's restricting enough air to keep the fueling rich enough to run.

The real trick is figuring out why it's too lean with the choke off.

What have you tried so far?

 

[NicoMec]

Choke on, fueling fine. Choke off, fueling not fine. You answered your own question. It's lean enough to stall out with the Choke off. Choke on and it's restricting enough air to keep the fueling rich enough to run.

The real trick is figuring out why it's too lean with the choke off.

What have you tried so far?

To be honest, I haven't done much to fix it, I adjusted my idling pin a lot and the throttle cable housing but now I know it's probably running lean none of that would've helped. Do you have any suggestions?

 

[Wrench]

To be honest, I haven't done much to fix it, I adjusted my idling pin a lot and the throttle cable housing but now I know it's probably running lean none of that would've helped. Do you have any suggestions?

Move the needle clip down one notch at a time
Moving the clip up it lowers the needle making it leaner
Moving the clip down it raises the needle making it richer

 

[NicoMec]

Move the needle clip down one notch at a time
Moving the clip up it lowers the needle making it leaner
Moving the clip down it raises the needle making it richer

The brass needle in the carburetor you're talking about im assuming?

 

[Wrench]

The brass needle in the carburetor you're talking about im assuming?

Careful don't loose the "Jesus Clip"

Jesus where did that clip fly off to

 

[NicoMec]

Careful don't loose the "Jesus Clip"

Jesus where did that clip fly off to

Will take note lol

 

[newuser3466]

I

So I have been running into this issue lately and I have not been able to figure out what's been going on. I figured it would be best to upload a video instead of me trying to explain it. But for context as you can see in the video, The bike was running/idling just fine and revving fine as well. Put the choke down and revved it again and then all of a sudden RPMs dropped and when I tried to rev it towards the end it almost sounds delayed and struggled to rev. It's gotten to the point where the RPMs drop so much that the engine just eventually dies out. (Apologies for the bad video and audio quality, it was recorded with a fake $30 GoPro)

I have the same issue someone help me out lol

 

[Wrench]

I

I have the same issue someone help me out lol

Same issue, follow the same advice given to @NicoMec.

​

 

[noah9988]

I tried to rev it towards the end it almost sounds delayed and struggled to rev.

That "blegh" sound when you crack open the throttle means it's not getting enough fuel. It's basically stalling the engine by a sudden intake of air and not enough fuel to ignite it. Also take into consideration that those carbs don't have an adjustable low rpm circuit. meaning you can't put in a bigger jet or adjust an air or fuel screw.