I have got a DR250 96 Model which is overall in good condition. Engine never opened up. It was running on stock carb which is Mikuni BST33. The carb was not in a good shape though often over flow leakage and mixture got out sync. Even after replacement kit didn't solve the issue.
So i thought to buy a new carb. Got this one from AliExpress. I know its a copy but reviews were good so i bought it.
Now the thing it after installation. Starting is improved a lot. Idle is fine. No missing there. Top end is fine i don't find any issue there as well. but it misses when i start pulling it from 20% throttle to upward. This missing is only when the bike is running. There is no missing when the bike is standing still. What could be wrong? Need guidance.
Idle screw mixture is one turn out. and you can see the float height in one of the picture.
The thing i observed it the air intake and out let cylinder of this carb is smaller than the stock BST33 carb. Could that be an issue? how to confirm that bike is getting enough air?
i don't know the jetting size as nothing is written on it but spec sheet says that main jet is 145 BST33 had 127.5 main jet.
The needle position is at 2nd level from top means fuel is already leaned. if we take it to middle it start giving black smoke on high rev.