Re: 1993 Suzuki DT 200 1200 rpm flat spot
I know this is a very old post but I thought someone should answer it so that others that have these older carburated engines would understand the problme and how to fix it. Its not uncommon at all.<br /><br />If you looked at the internal circuitry in the carbs what you would see is there is a passage from the air bleed screws to the venturi and to the float bowl. Just on the bottom side of the butterfly valves if you look closeley you'll see 4 very small holes, they are just about the size of 200 pound test stainless steel leader wire - keep that in mind. As you open the throtle you the butterfly progressively uncovers these little staggered holes and lets more and more fuel pass into the system as you crossover between the idle and the high speed circuit.<br /><br />If these little holes get clogged up it causes what you are seeing. It often happens that they do get clogged up after a carb rebuild that included soaking in heavy duty carb cleaner. I think its some sort of preservative coating they put on the aluminum of the carb body that becomes dislodged and starts to cause problems. Anyway after you do a real rebuild on them the problems start. Many times you can simply removed the flame retarder (air cover) and reach in with a bit of stainless leader material. Bend a chunk of it that is about5" long into an L with the leg only about 1/2". Poke it around in the holes and clean them out. Also, if you remove the air bleed screws you can blow air through them to clear the passageways. These things are the reason its real important to blow everything dry as soon as you take it out of the tank when you do an old set of carbs.<br /><br />Thom
