After runing my 250ex for a while, it stalls everytime I stop. It only does this after running for a while. I think it has to do with getting hot. Does anyone have any idea on how to cool it off, maybe a larger oil cooler, or fan on cooler or something. Also if it might be something else that I need to look at. Thanks

 

If you increase the idle speed, it might help. Just don't increase so much that it races when the motor is hot.

 

I had the same problem on a relatively new 250EX. It would not idle and was a beast to get started. You could hear a slight popping sound. I raised the idle speed as well, but I knew there was a problem somewhere. So I took the carb apart and squirted carb cleaner throughout the carburator. Put it back together and it ran better than new. I think I probably got dirt/sand in it from the last Glamis trip. Now I just barely touch the starter button and it purrs like new. Hope that helps.

 

yeah Ive been having the same problem after my motor gets really hot. like when playing in the mud where my tires are spinning and the air cooled motor isnt getting cooled. I put some thicker oil in mine. 20W50 and it works great now. the manual says in really hot weather you can use that thickness. and its been at least 90 here lately. and if it still does it just turn the screw an on the side of the carb out a bit while it is idleing and the motor is already warmed up. and yes cleaning out the carb wont hurt at all... do that too

 

atvwoody -

Is it hot where you ride (i.e., does your engine get overly hot because of climate)? If so, you are experiencing an overly rich condition in your idle circuit after the engine warms up.

This is perfectly normal; as the engine warms, it will affect your jetting. As the engine temp rises the air temp in and around your airbox, carb also rises - so now you have warm air being sucked in. If the engine is too hot (because its hot out or the engine is packed with mud), it will cause the air coming into your engine to be too warm. Since air becomes less dense the warmer it gets, you have less oxygen for the given amount of fuel your carb is providing. Too rich! If it becomes too rich, your engine will die (flood out), as you describe.

So in this case you need to lean out your idle circuit. There's a screw at the BOTTOM of your carb, right in front of your floatbowl that will do just that. Try turning it in about 1/2 turn, bet it'll take care of your problem.

Most of the time people have trouble starting hondas when cold, cause they're too lean. They need to turn out the bottom screw about 1/2 turn, maybe 1 full turn, and their starting problems go away. Its the same concept as above, just opposite.

Also, if it is hot where you ride, 20w 50 weight oil would be a good idea.

PS I do remember that our 250ex's idle was set a bit low, so you might want to adjust your idle speed setting (screw on side of carb) - but if your engine races when started cold, that's not the answer - above is.

ogre

 

whitch way do you turn the Thing on the bottom of the carb to be less lean?

 

counter clock wize .....like taking off a bottle cap