Logo
FULL SITE MENU

1994 150 HP johnson questions

R

Ramjamjungle

New member
I have a 1994 Johnson 150 HP Model J150EXERV---Having trouble with starting and carb flooding. I have a few questions I hope someone can answer. I rebuilt the six carbs with new gaskets and float needle/seats. etc. Bowls were warped so sanded them flat and adjusted floats etc. seems to me the needles should be able to stop the flow of fuel when the bulb is pumped however carbs are dripping fuel out the intake on most all of them if I pump the bulb. Can the bulb overpower the float needles or is fuel getting past the thin squiggly gasket that is embedded in the carb body backside and flowing into the carb throat?
My other question is---All the carbs have a vacuum port tube mounted on the body backside. These are all uncapped and open to the air. Doesn't this cause a vacuum leak into the intake? How does this not mess up the mixture?
 
When adjusting fuel floats you need to turn the carb upside down and let the float lay in the closed position. Holding the carb level and looking from the side, you should see a slight rise in the float from the hinge side (lower) to the far end (slightly higher.) I forget the exact measurement, but maybe 0.030" or so.
 
kevinj said:
When adjusting fuel floats you need to turn the carb upside down and let the float lay in the closed position. Holding the carb level and looking from the side, you should see a slight rise in the float from the hinge side (lower) to the far end (slightly higher.) I forget the exact measurement, but maybe 0.030" or so.
Click to expand...

Hi---Thanks for the info---already adjusted floats according to this instruction. My question is-- can the primer bulb force fuel past the float needle when the bowl is full? Doesn't seem like it should be able to push fuel past six closed float needles !! My current theory is fuel may be getting pushed past the thin o-ring type gasket between the carb body and throttle body. It would only need to breech a 1/32" fine line of o-ring to spray into the carb throat and drip out the front. Also the back side of these old carbs could be warped between the bolts creating a poor seal with the throttle body. The other thing folks should to watch for is the aftermarket replacement float bowl gaskets are of a material that has shrunk over the winter and does not take the shape of the top of the float bowl but in fact stretches almost straight between the screw holes and protrudes into the float chamber possibly contacting and hindering the movement of the float.I Have new gaskets on order from a different company and will see if this helps.
My other question is about the vacuum ports on the back plate of these carbs. They are for carb balancing but shouldn't they be capped off most of the time?
 
Back
Top