Merc 40Bigfoot restrictor plate

[smithmatbaker]

2002 40 Bigfoot 4stroke efi. RPM's low at WOT-4100-4200 range. Prop is as suggested by Merc. Engine seems to run perfect, just low rpm's. Reving in nuetral causes overrev horn at 6000 indicated by tach. What happens if I remove the throttle body restrictor plate? Is that what makes it a 40 as opposed to a 50 or 60? (Along with the ECM of course.) Will it lean out too far if the restrictor is not there? Do the bigfoots just run lower rpm?

 

[butlp]

Re: Merc 40Bigfoot restrictor plate

Mjsmith,<br /><br />I will try and answer some of your questions:<br /><br />1. The Bigfoot motors rev the same as the standard lower units, I think its 5500 to 5800 rpm<br />2. I think you have the wrong prop, discuss this with your dealer and see if he will lend you some different props to try.<br />3. I would not start removing anything on a new motor like yours. For one the warranty would be void and I do not think it is a simple modification on the EFI motors to increase to the 50 hp. There have been a number of threads on this board about trying to get more horsepower and the experts always seem to say you should trade yours in for a 50 hp as it would be cheaper.<br /><br />Hope this helps and you get the correct prop.