77 Johnson 70 HP No Go

[waldo177]

I am having yet another issue, I took it out for the first time yesterday and it starts just fine goes into gear great and where I put in the lake has a long no wake zone so I idle out and go to give it gas and it died start it back up and open it up in neutral for a bit what i think is cleaning it out if its loaded up put it in gear and can throttle it up and off I go go a couple miles and throttle down and idle for a bit go to open it up and it starts to die so I put it in neutral and open it wide open for a second and then back to gear and throttle up again just fine. Did this several times. Any Idea thanks

 

[oldcatamount]

Re: 77 Johnson 70 HP No Go

Sounds like you might need a good old fashioned carb cleaning. It's not difficult to clean and re-build a carb. No special tools are needed. The carb kits for your motor should be available at your dealer or, right here on Iboats.

 

[waldo177]

Re: 77 Johnson 70 HP No Go

I actually did rebuild them the only thing I didnt do was take the high speed or low speed orifice's out because when I tried they didnt want to turn but I could blow them out with carb cleaner and air and figured all was good and it will go upstairs with no issue in neutral. The only thing I didnt mess with yet is the fuel pump. Could that be a pssibility? The boat was sitting for a long time before I bought it and that the only part of the fuel system that has not been touched.

 

[oldcatamount]

Re: 77 Johnson 70 HP No Go

Disconnect the fuel line (that goes from the pump to the carb). Crank the motor to see if fuel is going through the pump. Since your motor runs good at high rpm for a few miles or so, the carb must be reasonably clean. Do you have an in-line fuel filter? You might check that for dirt inside.

 

[Big flop]

Re: 77 Johnson 70 HP No Go

When it starts to bog bump the choke, see if it gets
Better or worse.
Set link and sink. If throttle plates are not even
the carbs won't pull evenly. One or more may be lean or rich