400ex carb on 300ex bike

[Woogi]

Ok I tried searching but couldn't find much. I have a 300ex that the previous owner put a stock 400ex carb on it. I was wondering if any one had any jetting advise. I am in Houston, and the rest of the bike is stock, stock 300ex motor, stock exhaust.

[lester985]

welcome to the forum i think stock jetting on a 300ex is 120 or 122 main but having a 400ex crarb on a stock bike pointless there is no power gain from this carb go on ebay and get a stock 300ex carb it will run better

[Pipeless416]

Originally posted by lester985
welcome to the forum i think stock jetting on a 300ex is 120 or 122 main but having a 400ex crarb on a stock bike pointless there is no power gain from this carb go on ebay and get a stock 300ex carb it will run better

^wrong. im not sure on jetting specifics for a 300ex, but check around the 300ex section because i know there are many over there that have done this mod. its the same as putting a 450r carb on a 400ex..will it benefit more with supporting mods? of course. will it still give a power gain on a stock or nearly stock engine? yes.