Float bowls overflowing when titled up

[WinnerCougar74]

1974 Chrysler 135 hp. When ever I tilt the motor up, for example when trailering the boat, fuel drips out of the carbs. It seems like it comes from the float bowl seals. They are new and tight although I am afraid to over tighten them and strip them out. Maybe there is a torque specs. It also happen once while sitting in the normal position. Is was in direct sunlight. Is this a common thing with these motors or is it fixable?

 

[The Force power]

It's actually leaking out of the Carb.'s throat & normal when tilted excessive, (when trailering)

 

[WinnerCougar74]

So it's normal? Seems like it will damage my gelcoat and be a fire hazzard. Hmmm, hard to image they came from the factory like that. I don't remember other brands of ouboards doing that.

 

[Nordin]

As "may the force" says, it is normal when tilting the fuel comes out the carb throat.
The 3 cylinders with three carbs collect the fuel in the air silencer and lead it back to the crank case.
The 4 cylinders with two carbs do not have this design.

Other brands do the same, I have a 80Hp 4 cylinder Mercury from 1972 too. Has two carbs and it leak fuel through the carb throats when tilting.

 

[jerryjerry05]

Normal.

IF the tank vent's closed and the motor/tank sets in the
sun for a prolonged time, the fuel can be pushed out at the
weakest point.

If it's too much you can run the motor out of gas after your
done running,(not really recommended, that can damage
the cyl. over time).

 

[The Force power]

So it's normal? Seems like it will damage my gelcoat and be a fire hazzard. Hmmm, hard to image they came from the factory like that. I don't remember other brands of ouboards doing that.

Most 70's/80's Mercs. had a "catch-tray" and re-route the spill to out side the motor (into the lake/ocean)

 

[jerryjerry05]

Almost every carb'd motor I had did this.
Once I got the EFI not so much.

 

[WinnerCougar74]

Alright. Thanks for all the replies. I'll start thinking of how I want to handle the dripping. It's seems unsafe but I guess it's something that has been happening for years with most carburetor motors so it must be ok. Will it damage the gelcoat?

 

[WinnerCougar74]

Does using a fuel line shut off valve fix it?

 

[jerryjerry05]

Shouldn't hurt the gel coat.
Adding a valve probably wouldn't help either.
You can unhook the fuel line and then run the motor
dry after each use(waste of fuel) and over time it can hurt the
cylinders for not running with lube.

 

[WinnerCougar74]

If I come up with something I will post it. I might unplug the gas while idling into the dock before trailering. Might burn up enough gas to keep it from dripping out a lot.

 

[WinnerCougar74]

I added a shut off valve at my spin on filter assembly and it seems to help so far.