Hello all, I am new to MyVento, but a few days ago before I joined I was reading that someone was having problems with their 250 not idling properly when the engine is cold, and then when it heats up it is idling too fast. I also have had this problem among many others with my gator 250 YY250T engine by Jonway motors MADE IN CHINA piece of junk. I found out that the problem is sometimes not always with the carburetor, but with the settings of the intake and exhaust valves. These are not real hard to adjust if you take your time with them and do not over adjust too quickly. Be sure to note where the original settings are before you try any kind of adjustment.
I was able to get mine pretty well adjusted where it would run a lot better when cold or hot. That is, before I was on a long trip and blew the head gasket when cruising at a high rate of speed ( around 70 MPH ). I realize now, that it is too late, that these cheaply made bikes cannot sustain high speeds for any length of time, and please be well advised to keep a close eye on your oil levels.
I know mine had plenty of oil in it, before my trip, but I feel with the cheap and very thin gaskets, they just cannot handle long periods of a lot of pressure, which is what mine was going thru. I was able to make it home, but it hasn’t run properly since, and now is in a thousand pieces, until I can make gasket for it, and get it put back together.
Good luck to you all,
Ken

Well there is a reason that a Chinese made 250 can be had for under $2500 and a Japanese/Taiwan made 250 is over $4000. Well best of luck getting it back together.

Sold mine with 500 miles on it BEFORE it blew up.