Hey! Anyone got a clue as to why one of my late (Nov 2000) 2000 year model 250 hp fichts is losing a few hundred rpms at the top end range (i.e., wide open)? I feel a slight power loss too. This engine is the port side engine and has 610 hours.<br /><br />One person suggested checking the reed valve box, to make sure the screws are not getting loose.<br /><br />Another suggested it might be some carbon build up.<br /><br />I've changed the plugs twice and notice no difference & I recently added fuel injector cleaner to the tank.Not much help here yet either.<br /><br />With the computer plug in we see all cylinders firing right at idle + the fuel injectors check out OK with the computer.<br /><br />Another mechanic writes: The other possibility is the Throttle Position Sensor going bad.<br /><br />I remember a problem with one of these years ago.<br /><br />I think it could be a coil failing at top end - or a bad coil ground - causing intermittent fire - but which coil? How do I find the right coil? The coils checked out OK on the computer too, but that is at idle.<br /><br />The 2 sister engines have almost all their original power and rpm range is good. They have 710 hours on starboard and 510 on C/R middle engine. I still get better than 1 mile to a gallon on this 42 foot Performance Yacht (a cigarette hull) at 42 miles per hour - and I'm running three 250's.<br /><br />I don't fool with these - cause if they aint broke and are running right - don't try fixin' is the best mechanic advice you can get.<br />I had two fichts on a Scrabe 34 footer and could go 50 miles on 36 gallons of gas. With the 3 250s I can go 50 miles on 45 gallons of fuel.<br /><br />On Evinrudes carerator engines on the Scrabe I went 50 miles on about 55 gallons. I have fuel meters and use my GPS numbers for very accurate testing of the fuel economy.
