help 85 big red 250es bogs

[wildturkey47]

heres the problem. starts and runs with choke on. once hot will only idle and run with choke half on. can get it to run with choke off, but only while working the the throttle. anyting over half throttle with the choke off bogs down and exhaust overheats. backfires through exhaust not intake. put in new plug with proper gap and rebuilt the carb. sprayed with carb cleaner and compressed air, pilot screw 2 turns out. still same problem. where to go now. any suggestions would be great thanks.

[Flyingw]

The first things to check are the gas cap and fuel flow out of the petcock.

The gas cap vent tends to corrode and cut off air in to the tank. When its warm and running bad, take the gas cap off and see if that makes a differance.

There is a strainer thats slipped over the pickup tube on the petcock. Pull your fuel line off and open the petcock in both on and reserve. Check to see if you have a good flow out of the petcock. If flow is low, drain your tank and remove the petcock checking the strainer to see if its obstructed. If the gas cap and petcock strainer are good then you still have junk in your carb. Its doesnt take much to foul a carb.

If all else fails, I have rebuilt and tested ES/SX carbs on my shelf.

[dougspcs]

Take another shot at that carb!!

I've had to pull, strip and clean SX/ES carbs a couple times also to get them running right.

You are obviously having a fuel starvation issue on your secondary jet..check it closely again. Also make sure your float is opening and closing properly to get the fuel into the bowl.

[wildturkey47]

ok will try all suggestions. will let you know how it works out thanks again

[wildturkey47]

ok. fuel flow from tank to carb is good. cleaned carb again. now will idel indefinately without choke. will accept throttle with oaccasional backfire and or stall. rev, rev rev full throttle, let cum down to idle speed full throttle............stall. pilot is set at 2 turns out(havent messed with that) valves are noisy could this be the issue? if so does anybody have the procedure for valve adjustment. or any other ideas are welcomed. ive owned this bike since 1985 my first and most beloved machine. thanks for all your help!!

[greythorn3]

anyone know the stock carb settings on the 85 250es and what size jets and such, mines runing without a air filter or box so im thinking they had to richen it up plus its eating 2.5 gallons offroad in about 40 miles. seems like allot. also when running wide open for a while it seems to either carb ice or run outa fuel. if i wait 3 minutes or so it will start right back up. what the float hight supposed to be set at?