Running carb dry, yes or no ?

[Joe Reeves]

Re: Running carb dry, yes or no ?

(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!

 

[tx1961whaler]

Re: Running carb dry, yes or no ?

So....... leaveing gas in the carb from week to week Won't harm it any more than running in dry. Correct ?

(My opinion only) If you are running the motor on a regular basis, like daily or weekly, then I don't think it makes a darn bit of difference. If it is a portable motor that would leak gas all over you or your car, then that would be different. My motors (all single carbs) sit for months at a time, so I run them out. But Silvertip is correct; there is always a tiny bit of gas left in the bottom of the bowl that does not come out, so I may have been doing the wrong thing over and over for decades. Lately I have not worried about varnish but rather with this gummy white crud that I have seen in other small engines I've worked on recently. I don't know what it is, or how it got there, but I've seen plugged up tanks, lines, and carbs on weed-whackers that have set for months with white gum that I have not seen before. I'd hate to think that I'm going to have to run my little outboards on Coleman white gas to keep this form happening....

 

[wilde1j]

Re: Running carb dry, yes or no ?

I have run dry all motors for over 50 years and never a problem. That said, do not EVER run a DI motor dry. There you are looking at damaging a very expensive fuel pump, and/or at minimum, a trip to a dealer. That's the only exception, IMHO.

 

[rjezuit]

Re: Running carb dry, yes or no ?

On a 2 stroke, single carb engine, the fuel/oil mixture goes through the crankcase before the combustion chamber. If you run out of gas, the engine stalls when there is no fuel in the combustion chamber. The oil doesn't disappear instantaneously, so no problem. On a multi carb engine, you can be running on one carb/one cylinder. While not good, since there is no combustion in the chamber that is not firing, the rings are not loaded by combustion pressure, and thus not good, but not the end of the world either. Simple rule if you ask me. One carb. okay, multi carbs, don't. Rick

 

[psteurer]

Re: Running carb dry, yes or no ?

Joe Reeves has it right as always. Single carb motor no problem to run it dry, multi-carb a possible problem. The only exception I would add is that if you have a 4 stroke engine, then with today's gas run it dry.

 

[GatorMike]

Re: Running carb dry, yes or no ?

To those who's dad instructed them to run the fuel out like mine did. Unless your dads name was Ole Evenrudstuen or he at least had the last name Evinrude I would suggest you not listen to him.

Just my opinion. seems on some subjects our dads weren't near as smart as we thought they were.

 

[F_R]

Re: Running carb dry, yes or no ?

To those who's dad instructed them to run the fuel out like mine did. Unless your dads name was Ole Evenrudstuen or he at least had the last name Evinrude I would suggest you not listen to him.

Just my opinion. seems on some subjects our dads weren't near as smart as we thought they were.

Thanks, son. In ten years from now you will be amazed at how much we've learned in only ten years. My dad is gone, but I still remember the wisdom he passed on to me. He only had an eighth grade education, but he sure wasn't ignorant.

 

[tx1961whaler]

Re: Running carb dry, yes or no ?

I have still not destroyed my dad's 1950's and 1960's motors that have been run dry for the last 50 years. On the other hand, maybe they would have lasted 150 years if we hadn't been so destructive with them.

 

[71Windsor]

Re: Running carb dry, yes or no ?

Well. I use to run mine dry. But after some thinking and research I decided to just let mine go this year. For the first year since I owned the boat I DID NOT run it out of fuel. Instead I ran stabil on my last trip out than parked it. Just started it yesterday and had no problems started up just fine. So Ive changed my ways and will no longer run my engine out of fuel. I have a johnson 150 triple carb.

 

[KB1]

Re: Running carb dry, yes or no ?

Just now getting back to this because I knew you'd get all the info you needed. Only had one multi-carbed engine, did the same, never a problem in 20+ yrs.

That always worked well for me; some people SWORE that caused them probs.

AHHH! but it's SPRING!! Let's move on to important stuff!

 

[tx1961whaler]

Re: Running carb dry, yes or no ?

Important stuff, like why is it snowing in Dallas on Mar 20 when I want to go fishing??