i just got a 04 yamah blaster about a week ago and the PO said it just needed the carb cleaned out. it will start up and idle ok for a minute and then start loading up with fuel and die. if you give it WOT it will rev up to like 3k rmp and then start loading up but it will slowly raise rpm and then when you let off the gas it will return to a very rich idle . it runs good the first minute you start it up for the first time of the day. i have had the carb apart a good bit and have adjusted the floats to stock . i have cleaned every inch of the carb i can reach . i have the idle turned up a good bit so it will some what maintain an idle . im completely out of ideas.
cant figure it out. carb issue
- Thread starter tgra
- Start date
You may be flooding, is there any issue of fuel from the carb.
Is the air filter clean.
It is possible to check the fuel level by attaching a length of clear plastic tubing to the drain nipple , lifting it up the side of the carby, and cracking the drain screw.
The fuel should show in the pipe to the level of the carb body above the float bowl gasket.
Make sure that the air screw is only about 1 1/2 turns out.
Is the air filter clean.
It is possible to check the fuel level by attaching a length of clear plastic tubing to the drain nipple , lifting it up the side of the carby, and cracking the drain screw.
The fuel should show in the pipe to the level of the carb body above the float bowl gasket.
Make sure that the air screw is only about 1 1/2 turns out.
A rich mixture is caused by a few things, too much fuel (caused by flooding), incorrect jetting or too little air (blocked air filter or restricted passages).
There have been reports of socks stuffed in an air box to act as an air filter.
Has any thing found its way into the snorkel that feeds the air box?
Is the pilot jet actually fitted to the carb, it should be a 32.5.?
Try removing the air box lid to see if it improves, but do not ride it if it does.
Is the choke shaft going in fully?
Is the air jet passage free from obstruction?
The needle should be set on the middle clip.
There have been reports of socks stuffed in an air box to act as an air filter.
Has any thing found its way into the snorkel that feeds the air box?
Is the pilot jet actually fitted to the carb, it should be a 32.5.?
Try removing the air box lid to see if it improves, but do not ride it if it does.
Is the choke shaft going in fully?
Is the air jet passage free from obstruction?
The needle should be set on the middle clip.
I have started it up with the tube off and it still runs the same the air jet is a stock 32.5 and the main is a 230. Yes the chocke goes in all the way in except for like a mm . What is the little hole at the bottom front , throat portion of the carb. (not the pilot jet hole)
