00 honda cr250r popping noise

So I got a honda cr 250r awhile back I rode it a few times and then it started popping on decel so I took it to the shop and they told me the top end needs to be rebuild so I sent in the cylinder to get machined to stock specs and bought a top end rebuild kit (piston, bearing, rings, gaskets, etc.)

Slapped it all together and I'm still having the same issue the carbs all stock (needle, sj, mj, etc.) I don't know what I'm doing wrong I was told by another shop that its running lean.. Idk I'm lost.. Btw this is my first bike

A good place to start would be to richen the air/fuel mixture, meaning allow more fuel into your motor. It sounds from your story like its running lean, which means theres too much air compared to how much fuel the motors getting. This causes it to overheat and deprives the engine from the oil you mix in your fuel. You can try adjusting the air screw in which will allow less air into the pilot circuit, if that doesn't work, try adjusting the needle position to richen the mix. If neither of those work, you need to change the jets in the carb to larger diameters until your bike is running just right.

How fast do you decel? If you open the throttle near wide open, and close it right off it creates a vaccum within the carb, sucking in a ton of air to make up fir the lack of fuel

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now