Check out my posting here:
Triumphrat
In short:
"3-Checked gas cap – Some, maybe all, bikes are fitted with California emissions spec gas caps, apparently these caps are more restrictive on air flow than “normal” caps meaning a build up of pressure. At the recommendation of others, when I was experiencing the hic-up/stall problem they suggested to open the gas cap, when I did there was a definite whoosh/pop signifying equalizing pressure. The replaced the gaskets in the cap (converted it to a normal/standard gas cap) and that significantly improved the performance and eliminated the stall but hic-up was still present."
"I think the gas cap is an important thing to check and in light of all the other recommendations in regards to “gas starvation” issues and the significant whoosh/pop sound when opening the gas cap, this to me seems to be high on the food chain of contributors. Also, I now smell gas on occasion which I never smelled before the gas cap refit. I don’t know if that is good or bad but I think it indicates that there was a problem with venting through the cap before."
Think about it, everyone recommends the same thing and for gas starvation we all hear the whoosh/pop sound when opening the gas cap. Changing the gas cap or the gaskets in it seems to be a less evasive measure than removing the tip-over valve, and less dangerous.
AL