[GONZOKX]

Hey guys my sons 65 just started bogging down at low speeds. It idols fine and when you hit the power it takes off like a bat out of he*l. I changed the spark plug put new gas with the same mix ratio I have always used 32:1. I took the needle clip down one notch and it seemed to help a little. The bike a good compresion and ran fine two weeks ago. The weather has gotten a little colder from 60 degrees last time we rode to about 40 this weekend. Any tips on what I should start with on trouble shooting?

 

[griffbones]

Try turning the air screw in a half turn, it sounds lean due to the cold weather.

 

[GONZOKX]

The air screw is under the idle thumb screw right

 

[stevied645]

dunno if the carbs all look the same but my airscrew on my kx250 is on the bottom right hand side of the carb casing if your looking from the left hand side of the bike

 

[ikarus1]

it's the one you can't turn with your hand (smaller, toward the air filter more than the engine) but with a screwdriver

 

[GONZOKX]

Hey guys I turned the air screw in half a turn and it made a world of differance thanks a ton. But now I have another question how can I make the power of this little bike hit a little smoother. It seems like when im on it the throttle is real smooth then when it gets on the pipe it wants to throw me off the back. (Im 230lbs my son is 75lbs.) The reeds are good (stock) 2001 kx 65

 

[KickassKX125]

I'm not sure but maybe a flywheel weight. not sure really!

 

[griffbones]

A Fly wheel weight will help a little bit, depending upon how heavy of a weight you install. Two stage reeds can sometimes smooth the hit a little bit.
These little bikes don't have power valves so they do have some hit to them. But I bet your son will probably get used to it really fast.

 

[ikarus1]

Hey guys I turned the air screw in half a turn and it made a world of differance thanks a ton. But now I have another question how can I make the power of this little bike hit a little smoother. It seems like when im on it the throttle is real smooth then when it gets on the pipe it wants to throw me off the back. (Im 230lbs my son is 75lbs.) The reeds are good (stock) 2001 kx 65

Think about how your weight is distributed vs how a 75lb child would be.
That is why the thing is wheelie-prone - you are over the back tire near the balance boint.

Teach him the attack position: standing up, knees bent, elbows up, and weight over the front. It will be fast but kids learn fast, too.

I am teaching my 8 year old daughter how to use the clutch and gears, and to take out the hit I put a washer in the exhaust outlet. I am going to gradually grind the hole bigger until I can just take it out.

 

[GONZOKX]

When you say so try two stage reeds. Is that something that I put into my stock reed cage or is it something like v-force reeds cage and all?

 

[ikarus1]

Boyesen makes two stage fiberglass reeds that will bolt right into your cage.

 

[griffbones]

Yeah Boyeson makes two stage reeds that will go in your stock cage but,....... The most effective method of taming the bike down was posted by ikarus1, and that is the washer in the head pipe trick! This will do more to limit power and tame the bike than any of the other suggestions any of us have made. IMHO

 

[ikarus1]

Just be aware that this will make the bike run a little richer. It's not necessarily a bad thing, and will dull the throttle response a bit more. I haven't had any issues with fouling plugs.

I pull the washer out when I want to ride it