Diagnosis/Tuning help

[Jferdi03]

Breaking in the new engine today and it died a couple times. I have to hold the choke down while riding or it comes up and bogs me down. An elastic band would fix this I suppose but would running rich cause this and foul my plug? New plug allowed the bike to run again but same issue with the choke, it feels choppy when it starts up. I've never experienced this before.

I am thinking I need to lower the clip on the carb needle. I messed with the idle screw at the bike sounds way better at idle, but starts to die when given throttle now.
I have read many threads of others issues trying to resolve this on my own, need a more personalized answer. I'm a noob. Thanks

 

[Chainlube]

Breaking in the new engine today and it died a couple times. I have to hold the choke down while riding or it comes up and bogs me down. An elastic band would fix this I suppose but would running rich cause this and foul my plug? New plug allowed the bike to run again but same issue with the choke, it feels choppy when it starts up. I've never experienced this before.

I am thinking I need to lower the clip on the carb needle. I messed with the idle screw at the bike sounds way better at idle, but starts to die when given throttle now.
I have read many threads of others issues trying to resolve this on my own, need a more personalized answer. I'm a noob. Thanks

First off, take the air filter off and tighten the screw that holds the choke arm, if it dies when you're giving it the throttle, it's probably the float is out of adjustment.

Read through this thread for all your carb tuning.

Carby - NT Carb Tuning Basics

A few basics on the Happytime NT Carburetor:- Some pics identifying the basic parts:- Float Bowl Gasket Also see srdavo's NT Carburetor Assembly Pics for a bit more info. Brief Description Of Operation The NT side-draught carburetor operates by drawing air into the air...

motoredbikes.com

 

[Jferdi03]

I followed the carb tuning guide, adjusted the needle and everything ran good for about 20 km.
Was running fine this morning then the bike quit. My back tire will spin when I pull the clutch however it is seized even with the spark plug out if I don't use the clutch. I am being told to take apart the motor and look at the piston. This motor has like 20 km on it... anything to try other than tearing it down?

 

[DonkeyPooo]

how did it die? did it sputter out or did it you hear something give and everything locked up?

 

[Jferdi03]

how did it die? did it sputter out or did it you hear something give and everything locked up?

It was sputtering a bit before it quit. It felt like the bike wanted to stop a couple times and jerked me backwards but then recovered and propelled me shortly before it died.