i have an 86 250es big red and i do not know what is wrong with it this is what happens some time it idles fine then some time it dose not up when u punch it it bogs down and gas spit out of the carb but when i take out the plug it is realy black but it is not wet and the black stuff cursts or peals off
thanks for any help

 

my friend has a 85 250 big red and sometimes it wouldnt start and it would bog down and such. i work at a dealership and i cleaned the carb in the carb cleaner we have at the shop. the performance difference was crazy. the thing runs great and has no idle problems and is very respnsive. i bieleve that you might be running a bit rich so try turning in your air/fuel screw and remeber how many times u turned it in and try turning it out half of what you turned in. if that makes it worse or dosent help just put it back where it was. but your bogging and rough idleing seems to be a dirty carb problem. if you dont have access to a friend at a dealership or u dont wanna pay the cash to get it cleaned just rip it apart and use carb cleaner and a air hose and try and get as much gunk out of the carb and jets as you can. depending on how it was winterized in the winter might be a cause of the problem. at my dealership they recommend draining out all the gas out of the carb by unscrewing the little screw at the bottum of the carb. people say they just turn off the gas and run it but that still dosent get out all of the gas in the carb. i hope i helped a little and good luck

 

i cleand my carb 3 times and to day i took it apart again and cleaned all the jets out with carb cleaned and air to blow all the crap away and i put it back on and it still ran the same i try to paly aroun with the air fuel screw and sill the same do you think that my piston needs new rings i know it has a good top end because i redid it but all that was up there was the vales and i could not see the piston and it has a good head gaskit and lower gaskit from the looks of it from the out side do you think rings could do this because now i am startin to think that it is not the carb because when i cleaned it nothin realy came out

thanks for the help



who is faster you or your cuz

 

You mite want to check your floats if u didnt already see if there is any gas in them. also it could be your float needle is getting caught up which is making it flood

 

i dont think i can offer any help about the piston (i have yet to mess with mine, i am waiting to blow up my motor). off the line and through 1 2 3 gears i am faster then my cousin but with the nitrous he blows by me like he is in 2nd when we are in 4th and 5th. we have yet to try the nitrous in 1 through 3gears because we are scared to hit the limiter, because i suppose itt shuts the sprark off and when the motor fills with nitrous and then ignites BOOM! but the nitrous is pretty cool.check out his pics in his profile thing,his name is irule and then some numbers. sorry i coulnt help anymore with your problems

 

im with this guy i also own a big red and my compression went. first clue was the boggin and unreliable idle and starts specially in cold weather