How hard is it to change these jets? can you just take the bottom fuel bowl off to do it?? i have some knowledge on some other mikuni's on the two stroke motocross bikes are they the same??

 

Easy on the new HO's. Loosen the hose clamps on the intake and outlet side of the carb. Take off the support brace. You can now swivel the carb so the bowl is pointing to the right side of the machine. Take the hex plug off and remove the jet with a jet wrench or small screw driver. Be carefull that you don't lose the small washer. You may have to work with the throttle and choke cables to get them to give while you are rotating the carb.

 

so its a hex plug on the bottom? looked like a reg. nut glad you said something cause i dont have any hex keys at the cabin where i will be doing my testing,what is the best method you have found? i was doing a full throttle top end run to 60 then shutting it off clean.

 

No it won't take a special allen wrench to remove it, a small combo or cresent will do it. I just go by the book when jetting and have had no problems, but they always have the stock set up when doing it.