I have a 2000 2700 Pro-Line W/A that i just put newer motors on.
Original motors which are now deceased, were 1999 200 carbed Mercs getting 1.4 mpg at 4500 RPM’s running 37mph WOT 49mph @ 5600. 19 pitch prop.
Repowered with 2002 225 Merc EFI with under 100 hours on powerheads.
Using the same 19 pitch props… only getting .8 mpg at 3900 RPM’s running 37mph, WOT 53 mph @5700 rpm’s
My question is why would i be getting such worse fuel economy? I am using a Garmin fuel management that hooks into my Garmin 4212.
Would these motors throw off my management system? i have not filled the tank up to recalobrate (can’t afford 280 gallons right now).
Or am i just getting that much worse fuel economy? Thought i would be getiing a little bit better!
update… ran today and made it about 40 miles on about 70+ gallons of fuel.
So i have a real problem here!
What is the next step?
motor height is correct
it is proped correct, with no dings
EFI and carb engines get about the same fuel economy. The 200 carb engine has a ratio of 1.87:1; the 225 EFI has a 1.75:1 ratio. The EFI engines are running at a lower rpm for the same speed. That means they are running at a higher load since you are lower in the powerband making them less efficient. Changing the prop (net necessarily the pitch, but model) may help.
Are your engines getting up to temp? Efi engines run rich when cold because they are in constant warm up mode. Does your management system show engine temp?
3.0L mercs like the fuel, 2.5 mercs are one of the best power to weight to fuel burn motors out there. You also added at least 300 lbs to the back of that boat. What rpm can you get at wide open throttle? You should be spinning in the 5500 rpm range, you may need to reprop. I doubt you will get better fuel mileage with the 3.0L motors, but you may be able to get it a little better by re-proping. Now if you had gone with Opti’s, it would be a different story. You have to remember, those 3.0L engine were designed back when gas was $1.50 per gallon
After some reading up i have come to this conclusion…
Both powerheads were replaced and do not have a lot of hours on them… I read there is a TPI sensor that can be adjusted that will double your fuel consumption during break in period.
Any idea where this sensor is, or how to check it?
Know of any shops that can hook a Merc to a computer without waiting 3 weeks?
if the tpi is adjusted incorrectly, it wouldn’t be idling correctly, I think you have it confused with the break in oil mode, that doubles the oil from an electric oil pump(probably not on yours). Make sure your fuel flow gauge is reading correctly, fill the tanks, keep up with how much it says you are burning, end of the day, top off the tanks and compare