09 250 power issues

[Kleners]

A little background, we just finished building a ninja 250 that was looped. Only thing from old bike is the motor and rear swing arm.
After getting it running found out it had a blown head gasket. So tore the motor and carb apart. Everything is good no issues.
It is cold here low 50s (tx) I know it should be hard to start but I have to use started fluid to get it going. Then it's good.
Now I'm used to a newer gen 600 bike, but when I take this out it feels like it has no power.

Do you think timing could be off?
Carb seems fine, I'm going to do the shim trick on the needles to fix the cold and stall on take off stuff.

[csmith12]

Welcome John, what kind of exhaust is on the bike? Something doesn't sound right to me. Sounds lean to me. Is the carb jetted or shimmed?

[Kleners]

Stock exhaust. And no shims stock jetting.
It had new plugs, new air filter, and rebuilt carbs. But everything stayed stock.

[ChaoSS]

Originally Posted by Kleners

A little background, we just finished building a ninja 250 that was looped. Only thing from old bike is the motor and rear swing arm.
After getting it running found out it had a blown head gasket. So tore the motor and carb apart. Everything is good no issues.
It is cold here low 50s (tx) I know it should be hard to start but I have to use started fluid to get it going. Then it's good.
Now I'm used to a newer gen 600 bike, but when I take this out it feels like it has no power. As in freewAy in last gear and I'm at 9k to get over 60.

Do you think timing could be off?
Carb seems fine, I'm going to do the shim trick on the needles to fix the cold and stall on take off stuff.

The ratio of speed to rpms shouldn't have anything to do with the power, it has to do with the gearing. I don't remember what stock is, (my final drive is modified) but that doesn't sound right, which means either clutch is slipping, or the gearing is modified. How many teeth on the front and rear sprockets?