GY6 High and Low Altitude Problems

[Randallboy77]

I recently bought a fox carbide 150cc from michigan. the owner said it ran fine up there but when i got it down here in Louisiana it will run and accelerate but it is real sluggish and one minute it will run like a bat out of hell and the the next minute it barely moves. I adjusted the carb back and forth for an hour with no change. Do you think that because the bike came from up north that I might need to rejet the carb to get it to run right?

[smgs92]

i don't think that taking it from cold to hot weather would be an issue as i am in Ohio and i get summers in the 90s and winters below freezing and i dont have to do any modifications.

although you may want to check the oil perhaps hes running a thinner or thicker oil due to the weather, also you may wanna change the gas and clean the carb as those can be problems that cause rough idling and rough operation.

also i just thought of it check your belt and check to see if its real loose or missing teeth and check the TAV as those have given me the same problems many times and usually just buying a new belt fixes it. hope this helps.

[The tech guy]

Either fuel is restricted or the airflow is sluggish or possibly too much. Drain tank. New filter, check fuel lines. Clean the carb out. Should be three ports inside carb to be clear. Make real sure the carb intake doesnt have a crack, or isnt tightened down. The pulse lines to the carb need to be good. If there cracked or loose they will cause this. Then check/ replace plug. Check all electrical connections and make sure there snug.