Re: 335 surging when warm
I recently bought a nice X520 that had been sitting for a year and it surged at idle but ran ok at WOT. I poured the required amount of Seafoam into the the tank and ran it for about thirty minutes and it cleared up. Not guaranteed but it is a cheap and easy first step. After that, all of my experience with Kawas is the carb. I believe the Japanese culture is more refined than ours when it comes to taking care of machinery. They tend to be more focused on things like cleanliness and care of fuel and maintenance. That is why the Mikuni carbs are so much trouble for us. They were built for people who pay attention to their fuel and what they put into their machines. I do know that the Mikuni carbs have smallest orifices in a carb that I have seen and it takes only a mite that is almost not visible to change the operation of the engine. Good luck with your issue.