I have a 2002 Yamaha 130 2-stroke that continually fouls plugs after a day of fishing. It starts out fine but after a day of combined crusing and idling it will no longer idle. If I keep running it will start missing at higher speeds also. Take the plugs out and they are wet. I install a new set of NGK BR9HS-10's and it runs fine for a while but gradually gets worse. <br />I got the engine new in the crate and installed it (11 months ago) on a flats boat I built with a brand new aluminum tank so there is no gunk in it. It has had the problem since it was new and I originally thought it was due to the pre-mix I was running for break-in but no luck. I then got the shop manual and checked all the adjustments and found the oil injection pump linkage was a little off. I adjusted that and also set the pilot screws as low as as 1/2 turn but still no luck. <br />At this point I am about convinced that the motor is just not designed for any extended idling/slow speed running and am ready to trade it on an injected 2-stroke or 4-stroke. Any ideas on how to make this thing work or am I wasting my time?