Vented Gas Tank for 9.8 Tohatsu

[rocket rich]

I was just made aware of the possible problem with my motor?? Someone smarter then me ask me a question. When the motor lost it's prime was the tank venting or did I have a different problem?? I would like more info on the new way these motor vent, that is at high rpm's? I really don't know what I'm asking but ST Paul and the Bishop have the answer. Okay sock it to me....

 

[pvanv]

EPA-rated tanks don't have conventional atmospheric vents. They have valving that requires the tank withstand 5 PSI before releasing fumes into the atmosphere. Likewise, they must experience an internal suction before allowing air into the tank.

That means that you need a better suction from the fuel pump than with earlier designs. It also means that you must disconnect the fuel hose at the end of the day, or you could over-pressurize the fuel system, resulting in a ruptured diaphragm in the fuel pump, or flooding of the carb, just by having the tank in the sun.

 

[rocket rich]

the tank sets in my boat 24-7 in the sun but has a seat cushion on it. I do run it dry each day.. Is it possible to over fill the tank??? A lot to do with this 4 stroke motor. thanks again for your help. but am I to cover the tank or??? I do keep my boat in the water?

 

[rocket rich]

when you disconnet the fuel line On Both Ends??? I only do the motor side

 

[pvanv]

Disconnecting at the motor side is fine. If you suspect that the tank's vacuum "check valve" is not working properly, you can test by loosening the gas cap a quarter turn -- thereby allowing atmospheric venting of the tank.

 

[Sea Rider]

Leaving tank at heat environments no matter it's covered will end fatting the tank and creating more internal pressure build up, why don't you remove it from boat at boating day end and store it at a proper non heated place.

Happy Boating

 

[rocket rich]

too much problem lifting it in and out of the boat. No one told me about all the Maybe's on the 4 strokers tohatsu's. can we use a standard gas tank like a 6 gallon omc that came with my old 10 johnson motor

 

[pvanv]

Rich, diagnose the problem. Lots of old OMC tanks were also the non-vent type.

 

[rocket rich]

what's wrong with just letting the tank in the sun if you are fishing all day it's in the sun also?? Can't have your cake and eat it too???

 

[Sea Rider]

Rich, diagnose the problem. Lots of old OMC tanks were also the non-vent type.

Used to have same OMC 15 HP 6 gal red tank, assume was a non vented one, never really understood how it vented. Remember quite well that at sun or heated environment as in a car trunk used to become extremely fat, you could roll it over a flat surface as on deck. For my tranquility the cap was unscrewed a bit for pressure not to build inside tank. Used that way for years..

Happy Boating

 

[rocket rich]

can this tank be venting all the time?? Will the motor run as good??

 

[pvanv]

As you mentioned in another post, you can relieve the pressure by opening the cap slightly. The tank will take the pressure, just don't leave the gas hose connected to the motor.