I recently purchased a 02' Yamaha Breeze that wasn't running to good. It would only run at half trottle, anything more and it would shut down. I rebuilt the carburetor so it will start but only with the choke on and about 1/4 trottle before it cuts back or just shuts down. I really thought it was a carb issue and it still maybe, but my rebuild didn't seem to help. Now I don't claim to be a mechanic but I can think my way around most automotive repairs such as brakes, tune-ups, replacing engine part and even rebuilt my 9N tractor carb. I really thought rebuilding this Yahama Mikuni carb would solve my issues, but no dice. If anyone could let me know if this is an adjustment problem, poor rebuild, or maybe not even and carburtor problem at all. All feed back is appreciated

 

Have you done anything else to it? What do you mean by a rebuild. Were all the jets and passages cleaned of any build up? The symptoms seem to suggest a problem with the carb. It could also be a restriction in the fuel line or shutoff valve. It could also be a restriction in the air flow. You could also check the spark to make sure that it is not weak.

 

I agree it does sound like a carb issue. Make sure and take every part out of it that can possibly be taken out and clean it. Also make sure you air filtration system is clean. We did have a carb like this that no matter what we did it would not work. We borrowed one from a friend and put it on there and it ran like a dream. Go figure, sometimes it is easier to pitch the old over the shed and start out new.

 

Hey thanks for the reply, I stripped down the carb, removed all that I could(main jet, pilot jet, adjustment screws, orings, etc) submerged the body in tool/carb solution, blow out all ports, reassembled unit with new replacement parts and new gasket. I did check the spark plug, it appeared to be in good shape so I didn't replace it. When I reconnected the carb I didn't put the air intake boot back on only to save time in case I had to remove carb again, should this affect carb performance enough to cause my current problems.

 

your saying the intake side of the carb isnt connected to the airbox? if so then yea it will make it run lean. you gotta have everything connected just like stock with the airbox connected and the lid on. also adjusting the fuel enrichner screw might smooth it out a little, if it had been stored outside for a while from previous owner then maybe the sparkplug wire is dry rotted and isnt having consistant spark.