Running Carbs til bowls empty

[barry light]

I have always heard that when coming off the water for the day, to unplug fuel line to engine and continue to run engine until it quits, thus draining the carb bowls to keep fuel from sitting in bowls for extended period.

I acquired a 1992 Evindurde 115 hp ( crossflow 4 cylinder ) which has two, 2 barrel carbs. Each carb feeds two cylinders. Since the oil pump as been removed, I mix the oil with gas.

Is it okay to do this for this type engine? The reason I ask, that I am thinking if one of the carbs runs out of fuel before the other one does, the two cylinders would continue to keep the motor running, while the other two cylinders are not getting any lubrication because that carb is empty.

Is my scenario possible? If so, could this damage the engine? I just know with my experience with smaller one carb engines, that if you don't run the carbs out of fuel, and it sets awhile, it can gum up the jet in the bowl.

 

[Rick.]

Re: Running Carbs til bowls empty

For the reasons you mention I would not do it. Fine if you only have one carb. Opinions vary on this topic tough. Best of luck. Rick.

 

[Joe Reeves]

Re: Running Carbs til bowls empty

(Running Engine Out Of Gas)
(J. Reeves)

If the engine has but one carburetor, it's unlikely that running the engine out of gas would do any harm. When the carburetor runs out of the fuel/oil mixture, the engine stops running.

However, a engine that has more than one carburetor should simply be shut off. The reasoning is that the top carburetor will run out of fuel first due to gravity and the engine will continue to run on because of the still existing fuel in the other lower carburetors.

This results in having at least one aluminum piston running up and down a steel cylinder wall with improper or no lubrication. Not a good idea!

 

[dadtodc]

Re: Running Carbs til bowls empty

I did this for years with a 76 johnson, and I know the PO did the same because he told me to do it. One day I had some problems with pulling fuel in. Took it to a mechanic and he asked if I had run with out oil in the fuel. I told him no, and he said it looked like I had a lot. I told him I always run it out of gas every time and all of the precautions that had taken to make sure the motor runs forever. He stops me and says WHOA! you run it out of gas? I said yes. He said that was probably the issue. Said that while one bowl is out of gas the other isnt and keeps going. So one is lubed and the other is not. I agree with Rick on this one, and opinions do vary.

 

[Silvertip]

Re: Running Carbs til bowls empty

It is also impossible to run a float bowl completely dry so some fuel will remain.

 

[MRneatfreak]

Re: Running Carbs til bowls empty

I know the big fear for us 2 stroker's is phase separation in the fuel we use, either with ethanol or not. I personally wouldn't worry about the little bit of fuel that is in the bowls. You will be fine if you fire it up once a month or so, and use a fuel/water separator and or some of the additives out there. If you are really hell bent on it. You could drain the bowls with the drain screws on the bottom that cover up the high speed jets.

Again I would leave the fuel in there to make sure your seals don't dry up, and your float doesn't get a chance to get stuck in the down position (flooded).

 

[emdsapmgr]

Re: Running Carbs til bowls empty

Most folks run their engines frequently during the summer months. As long the engine does not sit for prolonged periods of time (like 2 months) you don't need to run it out of fuel. If you intend to store it for longer periods, it is good to get the fuel out of the carbs. Best way is to crack open the bowl drains on one side of each carb and let the fuel run out onto a rag.