Johnson 33 HP Fuel problem

Xandre

Petty Officer 2nd Class
Joined
Jul 18, 2006
Messages
143
OK I am 99% sure this is a fuel issue. I was out on Lake Ontario yesterday cruising around without issue. I decided to experiment with my rich and lean settings to learn a bit more about what these controls do. After playing with them a bit I set them back to my "normal" setting" and everything is fine.

I went to the dock to pick someone up and then the boat has a hard time starting back up. I struggle to get it going and have to really feed it a ton of gas. I open the motor door and see that when I pump the bulb fuel is leaking out of a hole and going everywhere ( see pic on link).

fuel.png


So the fuel is perhaps getting blocked and thus being pushed out of where it shouldn't?

Any ideas here?

The motar is a 1968-69 Johnson 33 HP Super seahorse
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson 33 HP Fuel problem

time for a carb rebuild, get a kit.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Johnson 33 HP Fuel problem

That hole is the bowl vent. There is a cork float in the carburetor and a valve that it operates. When the cork float rises it shuts off any more fuel from entering the carburetor tiil what is already in there is used. Then the cork drops, opens the valve and more fuel enters. Actually this goes on continuously while it is running.

Now, with all that theory out of the way, your problem is that:
The float isn't floating, OR
The valve is worn out and not shutting off, OR
There is dirt or crud in the valve OR.
You are mashing on the bulb way, way harder than reasonable, like with your foot.

Any of these will cause the fuel to not shut off, resulting in overflowing out the vent.

Cure: Clean and rebuild the carburetor with a repair kit. If you buy the kit from a dealer you will get a new float. If you buy a kit from an aftermarket source you won't get a float. Need I say more?
 

Xandre

Petty Officer 2nd Class
Joined
Jul 18, 2006
Messages
143
Re: Johnson 33 HP Fuel problem

That hole is the bowl vent. There is a cork float in the carburetor and a valve that it operates. When the cork float rises it shuts off any more fuel from entering the carburetor tiil what is already in there is used. Then the cork drops, opens the valve and more fuel enters. Actually this goes on continuously while it is running.

Now, with all that theory out of the way, your problem is that:
The float isn't floating, OR
The valve is worn out and not shutting off, OR
There is dirt or crud in the valve OR.
You are mashing on the bulb way, way harder than reasonable, like with your foot.

Any of these will cause the fuel to not shut off, resulting in overflowing out the vent.

Cure: Clean and rebuild the carburetor with a repair kit. If you buy the kit from a dealer you will get a new float. If you buy a kit from an aftermarket source you won't get a float. Need I say more?


Thank you very much for the reply here.

If all of those scenerios would cause the fuel to not shut off then why would the motor have a hard time starting up and staying on? Wouldn't the case be that there would be plenty of fuel for the motor to run but have extra fuel spilling out and into the water?

I will certainly read about rebuilding the carb and getting myself a kit. I appretiate your comments =)
 

Xandre

Petty Officer 2nd Class
Joined
Jul 18, 2006
Messages
143
Re: Johnson 33 HP Fuel problem

So today I went to the boat and thought I would try to start her up to see what would happen. I pumped the bulb and wasn't having fuel spill out of the carb and the engine started right up!

Infact it was sounding better and idled much smoother as well. Strange.

If the float was stuck it seems to have worked its way out and be functional again. I didn't take the boat too far away from my hoist just incase but everything seems to be running very well.

The lake gods are smiling upon me today =)
 
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