1977 Evinrude no top end power

[kingofbbque]

I have a 1977 70hp Evinrude. Sometimes it goes like crazy sometimes it wont. after letting it warm up I go to give it gas and it dies (sounds like it floods out) Have had it to 2 Mechs. and they say it is fine. Comp. great for that year motor.last Mechanic did carb. work and then lake tested it. I use it to fish and the wife wants to go tubing. It trolls great. I am getting yelled at cause it wont go fast when the wife wants it too. It has new plugs. new gas. Am new at this so I don't know were to start to solve problem

 

[Backlash]

Re: 1977 Evinrude no top end power

Hey King,<br />What size/type boat are you using? Trolling with a 70 horse motor could very well be causing a significant carbon buildup. Get some Seafoam and de-carb it (follow instructions on can). Hard to guess what the two mechanics you took it to checked. <br />Backlash

 

[kingofbbque]

Re: 1977 Evinrude no top end power

the baot is a 16 foot starcraft. after done trolling the motor run great put a tube on it and it goes only when it wants to (1/4) of the time usually, maybe, need a place to start looking to correct this problem some one please help

 

[Bear]

Re: 1977 Evinrude no top end power

I don't know yet but try this:<br /><br />Prime your bulb when this happens. Any difference? Then it is time for a fuel pump kit.<br /><br />Drain your carbs in a dry and clean glass jar. Look for water or dirt in the fuel.<br /> <br />Maybe stuck float valve. Maybe one does not open fully. <br /><br />Are all filters clean? The pickup in the tank too?<br /><br />Is there vacuum in the thank? What does the bulb look and feel like when this happens?<br /><br />Get back with more info and you'll get more suggestions. Good luck!

 

[kingofbbque]

Re: 1977 Evinrude no top end power

When the motor starts dying out and you squeeze the bulb in the fuel line it completely floods the engine. Fuel filter on motor is clean have not checked the pickup filter in tank. Tank has ventless cap but when this happens the fuel line and bulb look and feel normal. Trolled today for three hours then the motor went fast, stopped to put gas in tank and it wouldn't get up and go, trolled another three hours and it got up and went fast again. Right after loading the boat unto the trailer, we pulled the cowling off the motor and there was a small amount of water droplets around where the air box is located. We have a repair manual coming. Thanks Bear for your suggestions we will try the rest of them out.

 

[Bear]

Re: 1977 Evinrude no top end power

You can't flood the carbs by squeezing the bulb. If the float valves are working properly that is.<br />That is where I would start.