My 06 ltz 400 was running fine last night. I got on it today and I let it warm up for a minute then after 3 minutes or so of riding I stalled out and it was hard to start again and when it did it would die out. I let it cool down for a while and when I got back it was the same thing happening. I had the gas ON and it wouldn't rev at all so I put it on PRI and it ran but it seemed like I had to be more precise with my shifting.

 

Any answers would be good. It has a yoshimura full pipe on it. The guy I bought it from have me an extra carb because he didn't know how the previous owner did the jets because it is loud.

 

Check and make sure the tank vent isn't kinked. Sometimes that is all it is.

Pull the plug and see what it looks like. Try not to thank Suzuki too much for all the plastic they make you take off to get to it. If you don't know if it's jetted properly, and you can get it running, do a plug chop. If it's not, you need to rejet. A lot cheaper than possibly burning up a piston.