Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke button

[bigjslater]

1987 70hp Evinrude won't continue running unless manual choke button's depressed- I checked fuel pump and its working. All fuel lines running up to the carburators are clear. new fuel filter. So the manual choke chokes the air and causes the mixture to be richer ii the carbs. my suspect is either a faulty automatic choke or a problem with the carbs. Whats my next move?

 

[jonesg]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

order carb kits and rebuild them, theres gunk in them so make sure you find it.
If you have never done it, its very simple.

http://www.youtube.com/watch?v=o5cx...07A9BA566&playnext=1&playnext_from=PL&index=2

Might want to look over the whole fuel system from tank pickup to the carbs.

 

[kenmyfam]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

Sounds like it needs a carb rebuild.

 

[tashasdaddy]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

100%^^^^^

 

[bigjslater]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

thanks boys, carb kits on the way. It sure does take a while to get stuff
delivered out here in Hawaii.

 

[tashasdaddy]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

the price of living in close to paradise.

 

[bigjslater]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

well I ordered the carb rebuikd kits, took apart the carbs and there was no gunk. they were clean as a whistle. Does any one know how exactly the choke works?
I am suspecting that there is an automatic choke as well as a manual one and that it is not functioning.

 

[kenmyfam]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

well I ordered the carb rebuikd kits, took apart the carbs and there was no gunk. they were clean as a whistle. Does any one know how exactly the choke works?
I am suspecting that there is an automatic choke as well as a manual one and that it is not functioning.

No gunk or no "visible" gunk. Does not take much to clog a jet.

 

[bigjslater]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

clean as a whistle. I rebuilt the 3 carbs, put it all back together. Same exact
problem. Runs fine while choke button depressed, as soon as I let go engine
shuts down immediately. I looked into the carbs when it was running w choke
on and I could see gas in the carbs. So maybe my carbs are flooding out and
thats why its cutting out. Is there a carb adjustment somewhere to lean up.
I couldn't find anything in the manual.
My friend just caught 12 ono and a Mahi Mahi on the day I was rebuilding my carbs.

 

[crxess]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

Don't get yourself confused on what is happening.

When choke is released it quits running. That alone says it is NOT running rich.

Low fuel pressure - restricted fuel flow

Possible short in primary circuit? Bypassing issue while choked? Check for spark when Not choked.

 

[bigjslater]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

short in primary circuit???? now we must be getting closer to the problem
I found that my rectifier was totally charred. with the help of my neighbor
and a volt meter we discovered that with the primer button fully depressed and the engine running we were getting power to the ignition system. As soon as I released the button the power to the ignition was cut. He suggested to me that the rectifier alone was not my problem but that I Had a short somewhere in my wiring. WHen the button was released the wire grounded somewhere and killed power to the ignition. I studied the heck out of the wiring diagram in the manual. Im still Scratching my head as to how I find this bad wire. Any Ideas?

 

[Mike79]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

short in primary circuit???? now we must be getting closer to the problem
I found that my rectifier was totally charred. with the help of my neighbor
and a volt meter we discovered that with the primer button fully depressed and the engine running we were getting power to the ignition system. As soon as I released the button the power to the ignition was cut. He suggested to me that the rectifier alone was not my problem but that I Had a short somewhere in my wiring. WHen the button was released the wire grounded somewhere and killed power to the ignition. I studied the heck out of the wiring diagram in the manual. Im still Scratching my head as to how I find this bad wire. Any Ideas?

Did you find out what was wrong with it? I am having the same Problem?

 

[risewickb]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

Ok. I just bought a 1972 9.5 evinrude. I had the same problem. New carb kit. Cleaned the carb 3 times. ( the brother in law did most of the work ) This is where it gets interesting. If you look inside the body of the carb above the butterfly valve. There are 3 tiny ports. ( or there was 3 on mine).
I don't know how many times i used compressed air on these 3 ports. But being stuborn and getting angry knowing that SOMETHING was going on with the fuel. I kept blowing and cleaning spraying with throttle body cleaner. But low and behold... little fibers started to poke out these 3 little holes ... Thinking back a few days remembering the fuel pump rebuild We noticed the gasket where it was not compressed by the fuel pump body was deteriorating and swollen, Falling apart . Looked like paper mashe.
It appears these fibers worked there way into these little ports. So when the choke was on it delivered fuel. But take the choke off and these clogged ports killed the engine.

So now the engine purrs like a kitten....

 

[egorcenski]

Re: Evinrude 70hp 87 starts and runs w choke, dies as soon as I let go of choke butto

Ok, so it sounds like it's not a carb problem if you fail to get spark when the button is released. I'm going to assume that you have the choke built into the key switch. You have to push and hold the key in while starting it to choke the engine..... So after you said that you have a short somewhere I believe you may just simply have a bad key switch. If you look in this forum somewhere there is a diagram on where there should be continuity to the terminals on the keyswitch when it is in each position. Mark all the wires on the keyswitch and then remove them from the switch. Use the schematic and a meter to read out the terminals and I'm sure you will find continuity where you shouldn't at some point in that switch.