HELP!! I'm a charter boat operator here in alaska. I've had my Parker 2530 at the Yamaha shop for 4 months and I thought they had it fixed back in March. I ran it for about 3 or four hours and now it won't go above 2000 rpm. I have a Yamaha 225 two stroke. The mechanics seem to think there may be particulates in the fuel tank. The problem is that when running up on step at about 4500 rpm's the engine drops to say 3500 and may stay there or kick back in. It's got a mind of its own. I'm told as of a couple of days ago that now it won't go above 2000 rpms. I'm not to mechanically inclined, but any valuable information that I can pass on to more competent ones in that area would be greatly appreciated. Thanks.