1969 6hp mixture

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liz873

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Sep 2, 2009
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Picked up a 69 6hp johnson. Runs great but thats the problem no matter how far mixture knob turned in or out motor runs great. Put in gear under load runs great. Took carb apart several times cleaned it out no blockages, float good etc..Obviously gettin fuel from somewhere. Checked packing washers all good. Needle valve no burs, all new gaskets???
 
C

Cap'n Chaos

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Jun 4, 2010
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Re: 1969 6hp mixture

My 1962 6HP was the same way.... what was happening was the knob was actually just spinning on the shaft.
 
Joe Reeves

Joe Reeves

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13,262
Re: 1969 6hp mixture

Did you install the thick cork gasket on the high speed nozzle (Part #302984)?

The adjustable needle valve should have a sharp point on it. Does it?

If the fuel pump diaphragm was broken, one cylinder would be low in compression and the engine would load up. If running great, then obviously the fuel pump is okay. I suspect that you are overlooking something within the carburetor.
 
L

liz873

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Sep 2, 2009
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Re: 1969 6hp mixture

pump is good, tried it on my 1960 5.5 . Needle valve is sharp. I believe the high speed gasket is now a dense rubber like material. I ll open her up could be i forgot to put it in. thanks
 
lindy46

lindy46

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Re: 1969 6hp mixture

Needle threads into a barrel-like bushing which may be turning in the opening. Tighten up the packing nut.
 
Tim Frank

Tim Frank

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Re: 1969 6hp mixture

lindy46 said:
Needle threads into a barrel-like bushing which may be turning in the opening. Tighten up the packing nut.
Click to expand...

I think the needle threads directly into the carb body; if the needle is turning, it is moving into or out of the seat as it should.

The most likely scenario is that the packing nut is ALREADY too tight, and as one poster suggested, the knob is simply turning on the needle shaft.
LOOSEN the packing nut until the knob will turn the needle shaft.

There is usually a stop that limits the knob to one full turn. Best practice is to adjust the mixture to the optimum point and then centre the knob.
 
L

liz873

Seaman
Joined
Sep 2, 2009
Messages
68
Re: 1969 6hp mixture

Tim Frank said:
I think the needle threads directly into the carb body; if the needle is turning, it is moving into or out of the seat as it should.

The most likely scenario is that the packing nut is ALREADY too tight, and as one poster suggested, the knob is simply turning on the needle shaft.
LOOSEN the packing nut until the knob will turn the needle shaft.

There is usually a stop that limits the knob to one full turn. Best practice is to adjust the mixture to the optimum point and then centre the knob.
Click to expand...

Disassembled, and cleaned out carb, all gaskets good packing good, needle good it threads directly into body and is turning-not just knob. After cleaning i noticed the engine to idle down a bit when screw turned all the way in but wont stall like my other 5.5's Runs great all gears in tank so I'll leave it for now. Maybe main jet oriface was opened up a bit by previous owner so she always is getting a little gas in. Thanks
 
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