I have a 2003 vmax 200 hp motor that blew three years ago and they replaced the powerhead. It probably has less than 100 hours on this powerhead for a little update on motor. It lost a fuel pump two months ago, got that replaced and had a water seperator installed, and now it has another problem. When I run down the lake it runs great, starts great but after I run for approximately 4 or 5 miles it will lose power. If I am running at 5000 rpms it will lose at least 500 to 700 rpm's maybe a little more but it continues to run but it feels real sluggish and has no top end speed once this happens. I have had yamaha's before and I have never had this happen before. I checked the o2 sensor and it had no carbon build up inside of it. Could it be a faulty o2 sensor. One other thing it seems like it is getting worse gas milage than ever before...it never got good milage but I think it might be worse.
