My 250 trailblazer wont start without the choke wide open. The weather is finally getting nice out and I had no problems all winter. What could the problem be?

 

pretty sure that if you need the choke to start it...its needing more fuel. therefore, jet up a little bit.

 

Could be condensation or dirt in the carb.....
It's hard to explain... I would remove the air filter... make sure it is clean...
Find the carburator vent hose... the one line that isn't attatched to anything..... and blow air through it until you have flushed the carburator....
You flush the carburator out the over-flow line.... probably attached to the air box....
Now.... If that doesn't work... make sure your throttle cable is not bound or out of adjustment.....
Once you have gone that far and it still won't run correctly.... then shoot for adjusting the carb...
I have always found that you should never adjust a carb unless it is your last resort.... Hard to get them just right again...
Just trying to help,
Jon

 

if this just happened out of the blue then pull your carb out and spray it out with carb cleaner.it's most likly a clogged pilot jet

 

Check your compression. It may be time for a rebuild.