Early 90's 30hp evinrude

[Riverbean]

What would cause the motor to only run at WOT with it fully choked and not run WOT with it not fully choked?

 

[Pappy]

The more information and history you provide on the engine the more complete and informed the answer will be.
Welcome to the forum however!

 

[Riverbean]

It starts up and idles and runs ok to about half throttle then it dies but if I pull the choke out it will run all the way up to WOT but soon as I push the choke back in it dies...

 

[GYPSY400]

What would cause the motor to only run at WOT with it fully choked and not run WOT with it not fully choked?

To answer your question, you have a restricted fuel flow somewhere. By choking the engine you are reducing air flow so the fuel/air mix is sufficient for combustion.
As Pappy said, we need more service history to give a suitable answer. It really helps if you tell us if it started all of a sudden, over a period of time, or worse - if your buddy just 'fixed' it.

Sent from my SM-G960W using Tapatalk

 

[RaisedByWolves]

Youre playing with fire if you continually run it like this.

 

[Riverbean]

Couldn't tell you any service history as it was a curbside freebie. I figured it was a fuel delivery issue and have the carb completely apart and soaking as I type this and have a carb kit ordered also so ill start there and see what happens. To the other post, yes I agree and only ran it for about 10 seconds twice and brought it home and took the carb off and posted here...when I get it rebuilt and try it I will post back my results....thanks guys!

 

[DriftinMT09]

I have a 1990 Johnson 30hp, which is likely the same engine setup you have. My choke knob doesn't move a butterfly or a valve inside the carb, but rather seems to allow fuel to be pulled from the bowl and sucked into a small port in the top of the carb just before the throttle plate.

Either way, definitely sounds like you have a clogged or restricted carb port that won't give you the fuel necessary under your half or more throttle position. IF I know what I'm talking about, the main jet is in the bottom of the carb, accessible when the bowl is off. If I had to guess, that is plugged with sediment or scale.

 

[Riverbean]

Got the kit and put carb back together and still the same...removed both orifices and the high speed was clogged, got it unclogged and it runs now at WOT....idles rough but for free I can't complain, gonna put new plugs and wires and run some sea foam through it and see if it helps....

 

[nccatfisher]

Did you soak it in cleaner or at least spray all compartments out with cleaner and blow out with compressed air? Some really bad ones you have to get after with tip cleaners or small wire if they have scale in them.

 

[Riverbean]

Soaked it, used small picks (small wire) and yes I blew it out....tried slow speed needle to lean it out till it sneezed and turned it richer, several times and still idles poorly....also warmed up engine first. I did notice the cam starts to open just before the two marks but when I tried to adjust the link to the throttle the little stopper is all the way to the end if that makes sense....

 

[Pappy]

Have you ever checked compression on the engine?
Basics always help.

 

[Riverbean]

Yes sir.....112 and 109.