I'm having problems with my motor. problem suddenly started. i have a Nitro Savage 884 with a 150hp mariner outboard. i seem to have lost 500-800 RPM's. the boat has a real hard time getting up on plane now and i have lost 10 mph. at about the same time the tach started acting funny, dropping to zero RPM's periodically and the trim guage doesn't work. any ideas????? thanks.<br /><br />p.s. motor starts and idles fine.