I have a 1999 Scrambler 400 4x4. I ust today took the carb apart and cleaned it, and I am still having the same problem. Idles fine and when I ride it is run ok,not great, but ok. When I hit full throttle it dies off, almost choking out, if I let off and get back on a little it is fine, seems to be flooding. I took the plug out and it is soaking, can anyone give me some idea, why would it get so wet? Any info would be great.

 

tell me your elevation the temp mods if any and you current main jet size. does this happen all the time or just when you get to a quarter tank. they like to suck air instead of gas at that point. try it on reserve. check the fuel filter.
does it come back when you flip the choke or does it make it worse. that would be a tell tale sign whether you are rich or lean. does it do this to the point that it quits or will always keep running. a clogged passage in the carb can be a problem to

 

I am in Raliegh NC and I am not sure of my jet size, I believe the bike is all stock, so I am not sure of the factory jet size. I have not tried it in reserve and I am about at a 1/4 tank so I will try this as soon as I can. If I flip it on choke, it will kill it. I just cleaned the carb but I may have missed something. My main notice was the sparkplug was soaked with gas and oil. And if I was to keep the throttle pegged it would cut it off, but if I let off and then get back on it not as hard, I have to work back into it, it will go again, but as soon as I hit full throttle, same issue.Thanks for the help, I was beginging to wonder if I was going to get any replys

 

well first i'll explain my choke queastion if you already haven't figured it out. It is possible to have something so lean that it won't make enough heat to burn down. so in this case if you pull the choke you cut of some air making a richer air fuel ratio which in turn will make it run better so if it is rich the opposite will occur.

straight from the back of a mikuni pocket tuner symptoms engine condition worse

a. performance is flat not crisp

b.condition is worse when hot

c.condition is worse when the choke is used

d. dark fouled spark plug

e. removal of air cleaner helps

f. exhaust popping or back fire

g. engine sound is dull

lean conditions

a. acceleration poor, surging

b.performance improves slight as engine warms

c.better performance when choke is on

d. no color, overheated spark plug electrode

e. removal of air cleaner makes condition worse

f/ popping back through carb

g. engine pings or knocks, excessive engine heat