I pulled the carb and cleaned it out completely. I think you are right about the diaphram but I couldn't find a hole or tear in it. The reason I think that is the problem is because if I blow into the vent tube on the carb, depending on the amount of trottle I give it, it will run fine. But soon as I quit blowing onto it, it wants to die. What do you think?

 

Pull the airbox lid off, pull the rubber gasket out, and replace the airbox lid (thus allowing a bit more air into the airbox on acceleration).

See if this helps (not the solution, however a good troubleshooting step)

If this helps, then you may have jetting issues.

 

There is one thing I thought was odd about the diaphram, and that is it was kind of like it was streached like a ballon when it's been deflated. I don't know what it's suppose to look like, most diaphrams I have seen look like and automatic sprinkler valve. Anyway I guess I will order a new one tommorrow. Thanks again for the suggestions. I will let you know how it goes.

 

I had the airbox lid off completely and sometimes without the air filter on as well trying to see if it was an air problem. It still wanted to die past idle.

 

Take the top off the carb and check the diaphram and clean it also.

 

That's because there's too much air...

Take the gasket out, then replace the lid.

 

I pulled the gasket and replaced the cover and still same symtoms. Accelerates a couple hundred rpm and then dies.

 

a long shot, but what about a vaccume issue. not enough. maybe the line is messed up maybe crank vent is plugged. just a thought. also make sure its getting plenty of gas and theres not a bad petcock like someone else just found to be his issue from lack of fuel.

 

The diaphram shouldn't look like a stretched balloon, if so, there is probably too much stretch in the rubber that it won't pull the slide up quickly enough or far enough. Maybe a picture or two of the diaphram (in the carb with top off and out of the carb) would help me diagnose it and give you further tips. I worked on and tuned 40mm CV carbs for a few years back when I had a Harley, and got fairly efficient with them.