rebuilt carb, what next?

Lamarg33

Cadet
Joined
Oct 5, 2008
Messages
18
I?m hoping that someone has some idea of what I should do. I have a 1967 6 hp Johnson that won?t idle. I searched the forum and found that most recommendation were to rebuild the carburetor. So I did. But I am still having the same problem. The motor runs smoothly from a ? to full throttle. But go below that and it spits and sputters and finally dies. Then it?s hard to restart. The lean/rich adjustment has to be turned in almost all the way to keep it running at a ? throttle.

So, if I didn?t mess up the rebuild, what else could it be?
The points do need to be replaced. And I believe that it still has the original coils.

Oh yeah, after the engine dies, I have to pump the primer ball a couple of time because the gas in the line is used up.

If anyone has any insights, I would greatly appreciate it.
 

blimp

Petty Officer 1st Class
Joined
Sep 30, 2009
Messages
237
Re: rebuilt carb, what next?

could be the fuel pump. If it is a vacuum driven pump it could be flooding at lower rpms (and higher rpms, but you don't notice it as much). a small perforation in the fuel pump diaphragm can cause this.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: rebuilt carb, what next?

Try pumping the squeeze bulb while at the lower speeds and see if it improves, if it does you may have a weak fuel pump or an air leak.
 

oldcatamount

Lieutenant Commander
Joined
Apr 4, 2010
Messages
1,740
Re: rebuilt carb, what next?

I agree with Blimp. Sounds like a fuel pump issue. But you might consider doing the points and plugs to. I just sold a '67 6hp Evinrude last night! Hated to see it go, great motor and easy to work on if they need it.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: rebuilt carb, what next?

Is the tank vent open and clear? Fresh fuel? Water/debris in the tank?

Usually if the fuel line is loosing pressure at a connection point, you can hear the wheezing sound of sucking air when you squeeze the bulb, if you listen close.

Watch close under the cowl for a fuel leak while squeezing the bulb. If gas comes out the carb throat when you squeeze the bulb, your float valve isn't seating good. Either worn out or misadjusted.

Then try the squeeze test while under way. If it doesn't help at all, the fuel pump is ok. Alternative test for the fuel pump, is to unfasten it from the engine and pull the starter rope a couple times...if fuel comes out the hole on the back (where it attaches to the crankcase), the diaphram is perforated and needs replacing.

Primer bulbs and quick-disconnects do wear out eventually, so a replacement wouldn't be a bad investment.

You can test the ignition, with an inline spark tester (couple bucks at autozone). Set the gap for 1/4", clip it to the engine block, attach the plug leads (one at a time) and look for a strong blue spark while cranking. If it jumps a quarter-inch gap in the open air without a spark plug, it's firing in the hole under heat & compression.
 
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