425 hours, lately it has been more difficult to start. Normally it would start right up and go. Now it starts maybe 2nd try and runs rough for the first 30 sec or so. It will idle up to full RPM but falls flat with any load and will almost stall. I normally idle around 1K and warm it up 5 min before moving. After running at a fast idle (1200 RPM) for about 25-30 min it will work normally. I am not sure if I am getting full power, but everything seems to be working once it is hot. I have changed the air filter and the fuel/water separator filter. Where else should I look?