I am new to this site and I'm no mechanic so please bear with me.
My 425 magnum seemed to be running rich, it was on occasion pouring out smoke and dying. If I got on the open road and opened it up it would usually clear up the problem. The last time this happened it would not run. It sat for a couple months before I got to it. When I checked the oil it was over full an I think it may have gotten some gas in it. I changed the oil and filter and removed the carb to try to slightly adjust the bowl float level. After that adjustment the engine will run but only with the choke on or with throttle. The idle adjustment screw seems to have no effect at all. It is still making a lot of smoke when the choke is on. I have messed with the idle adjustment screw so much now that I have no idea where it is set at. Can someone give me th basics for re-setting the carb adjustments and maybe give me an idea of what to try next to get it to run without the choke? Any help will be appreciated!

 

The needle and seat are bad in the carb, this will fill the air box and crank case with gas, order a new one, the last one I did was $25. , take the carb off, take all the jets out and clean everything with carb cleaner. The float should be level with the bottom of carb when upright, change the oil and filter again and TURN THE GAS OFF WHEN NOT IN USE. You will never have this happen again if you do this one thing.
Oh yea, the air screw should be out 1.5 turns and idle will be as needed.

 

Replace the float needle and seat. Also replace the slide needle and nozzle.

 

Thanks guys, I believe you are right about the needle and seat leading to fuel in the crankcase and I admit to not turning the gas off like I should. Should I expect the needle and seat or the slide needle and nozzle to correct the problem of "no idle without choke"?

 

That happened with My warrior once. What I did to correct the problem out on the trail (that's when it happend) was to open the floatbowl drain screw and let her run a stream of gas into a container for a minute or so. That seemed to flush through the dirt and whatnot that was pluggin things up. The reason it would run with the choke on but not off was that there was not enough fuel getting to the engine, so choking off the air supply brought it back in check .. but only for idling not for riding ..

 

If you thouroghly clean the carb while you have it apart it should fix it, let us know how it works out.

 

Really???Turn the gas off when not in use ?

 

the only time i turn the gas off on the 450 is when its being transported. w/ the bike shaking backin forth it might make the float jump enough to flood the carb. but w/ it just sitting there unless theres dirt or something in the gas then it could sit there until hell freeze over and not leak past the needle. just my .02

 

Thanks again for the advice! I will get some new parts, clean her up real good, set the float level, adjust the idle and I'll even keep the gas turned off. I do appreciate the help, now I have a plan!