1987 115 inline 6 carb issue,

[James R]

This may have been an issue before I acquired this motor. I have rebuilt the carbs, side chamber type, with new kits after a thorough cleaning as I usually do. The upper and middle carbs are working ok but the lower carb shoots fuel out of the vent and carb throat when the primer bulb is used and whilst the engine is running. Of course the motor will not get up under load. I have gone over the carb again, replaced the float with two others and replaced the new needle with another. Blowing through the fuel in connector and applying very light pressure on the needle lever mechanism shows a good seal at the needle. The needle levers are set to the Manual specs as are the other two carbs. I have checked that the seat is correctly fitted.
Any thoughts on this would be greatly appreciated.
Thanks.

 

[GA_Boater]

When it's venting fuel the float, needle/seat or float height adjustment is not right.

Those are the only things other than the float and needle not moving freely that can cause this.

One other thing to check for is burrs on the needle seat. It doesn't take much keep the needle open.

 

[racerone]

Revisit carburetor work----Something is still wrong.

 

[James R]

Thanks for your responses Guys. I am sure all will be revealed in due course. I have examined the new valve seat and it looks fine. I will try replacing it and in the mean time I have ordered a good used set of carbs. I hope they are good anyway.
Thanks again.

 

[Toddo1969]

Had the same thing happen to me, turned out to be one of the floats full of fuel.

 

[James R]

Ordered a set of replacement carbs and rebuilt the needle action on the top for the offending carb. No change. Cleaned the replacement carb and tested. No flooding. Looks like the float was hanging up. Some roughness in the float bowl but not unusual. We have the answer.
Thanks guys.