Evinrude 120 Fuel system help

[truax42]

I am running an Evinrude 120 1989 model. I have replaced the fuel pump and cleaned/rebuilt the carbs and it runs great with the exception of random spells of acting as if it is not getting any fuel..... i can open the throttle and it will just bog down.....after a few minutes of this (and after opening the throttle) it will just go as it should. i think the best way to describe it would be a major fuel restriction then whatever was blocking passes through and it runs fine. i though it was loading up, i can clear the carbs but that doesnt help. a new fuel filter did not help either. would a bad plug cause this? they were replaced last fall. any ideas would be greatly appreciated. <br /><br />i am also trying to get more RPM's out of this 120. I have it on an 89 stratos fs 279. I am running WOT 4900 rpms. I know there is more power to be gained, but i just cant seem to get it to come out. The prop is a 13 1/4 x 21 3 blade ss prop. any ideas here? what would be an acceptable WOT range?<br /><br />Thanks for the help guys.

 

[truax42]

Re: Evinrude 120 Fuel system help

forgot to list my other problem.....speedometer does not work, i know absolutley nothing about these.....any ideas on how to troubleshoot/repair these?

 

[Cricket Too]

Re: Evinrude 120 Fuel system help

Souns like you missed something in a jet when you rebuilt the carbs and when you pass from one jet to another you get a restriction and then you move on to a clear jet. I would pull those carbs again, clean the jets with a piece of wire and some spray carb cleaner and compressed air. Your WOT RPM is way too low, you are lugging the hell out of that thing. Drop that 21 pitch prop and try a 17 pitch, you should be as close to 6000 with a normal load as you can. As for the speedometer is it a wheel type on a transducer? Sometimes the wheels stick or get busted, take a look at it.

 

[Dhadley]

Re: Evinrude 120 Fuel system help

What position is the tach set on?

 

[truax42]

Re: Evinrude 120 Fuel system help

dont know much about the tach, dhadley. how can i check the setting? <br /><br />the only thing i can find on the boat that may be related to the speedometer is a whit plastic tube at the bottom of the transom, it is 3-4 inches long. would this be the transducer for that?<br /><br /><br />as far as the prop, i ran what michigan wheel recommended based on my setup, guess they may have missed this one huh?