Yamaha Yamaha timber wolf baja 250

[silver98mustang]

I have a baja 250 that has some sort of carb problem. When the bike is cold it does fine, but when it warms up It spotters and sputters pretty bad. I have bought a new carb and it didn't help. Pulled of the air box lid, and left it one, but neither helped or hurt. I have adjusted the valves with no help either. I believe the bike was made in new Mexico so could the bike be jetted for that altitude. I am located in NC about 1000ft above sea level. I'm not sure but it might be a vacuum carb, would the sputter be caused by a lack of engine vacuum?

[shspvr]

How old is the Timberwolf Baja 250?.

There could be a few things it could be.

What about when on/off gas

Jet to small or to big as in pilot jet to main jet

Have you done compression test with wide open throttle on each test start with a cold test without any oil first then with a shot of oil (about teaspoon full) down the spark plug hole then warms up test if there a big difference then you should think rebuild it.

It possable it need a Valve Job.

What dose spark plug look like?.

[silver98mustang]

I just gave it a valve job, and the spark plug looked perfect with a nice tan color. it doesnt blow smoke so i figure the piston rings and compression are good.

[shspvr]

I just gave it a valve job, and the spark plug looked perfect with a nice tan color. it doesnt blow smoke so i figure the piston rings and compression are good.

Have you try opening or closing the pilot screw/air screw half turn to full turn more?, Or see what you have in pilot jet size may you have and up by one number higher.

[silver98mustang]

i have not tried that yet, ill try it tomorrow.

[silver98mustang]

adjusting the air/fuel screw didnt help. And from my understanding the carb i have doesnt have a pilot. could this be caused by timing?

[shspvr]

adjusting the air/fuel screw didnt help. And from my understanding the carb i have doesnt have a pilot. could this be caused by timing?

It possble if the timing is off by one tooth on the cam

All carb have to pilot screw/air screw and Jet or they will not idle

[silver98mustang]

it does have a pilot but is non adjustable be to it being a vacuum carb. i will check the timing soon

[shspvr]

it does have a pilot but is non adjustable be to it being a vacuum carb. i will check the timing soon

See this where need to look see below web site

http://www.quadparts.co.za/carb.htm

There all pettey much in same place unless it small motor 200cc or less they are usely on back side of the carb and sometimes in front

[Bthomas22]

I have Timberwolf 250 also. I rebuilt the carb set the timing and still have an issue which I think is the vacuum. But I can't find it for some reason. Any help or places to find a manual or diagram?