Is it better to drain the carb or not?

[BSDenning]

I own 2 outboard motors:
1. 1957 7.5 hp Evinrude Fleetwin
2. 1962 10 hp Evinrude Sportwin

I have just recently rebuilt the carburator on the 7.5 hp and I'll soon be doing the same thing with the 10 hp. I want to take good care of my carburators after rebuilding them, so that they will function as well as possible for as long as possible. My question is this: Is it better to disconnect the fuel line and run the fuel out of the carburator after each time operating the motor, or is it better to just leave the fuel in the carburator?

I've heard conficting opinions on this. Some say it is better to drain the carb so that it won't get gunked up and others say it is better to leave the fuel in the carb so the gaskets won't dry out and crack.

So, what is the consensis of the experts here?

I always run my motors on 87 octane with 24:1 Penzoil TCW3 Synthetic Blend Premium Outboard Motor Oil. http://www.pennzoil.com/products/marine/synthPremPlus.html Normally, I do not put fuel stabilizer in my motors, but the last time I run the motor for the season, I normally try to put some fuel stabilizer in the tank.

 

[Gary H NC]

Re: Is it better to drain the carb or not?

With Stabil in the fuel leave them full.
Running the carbs out of gas is asking for engine damage.Yes,it runs out of fuel but also runs out of lubrication.....

 

[tashasdaddy]

Re: Is it better to drain the carb or not?

both motors are single carbs, so it is fine to run them dry. multiple carbs, the top carb runs out first, this the top cylinder does not the lubed.

 

[BSDenning]

Re: Is it better to drain the carb or not?

Ok, so Chief of the Boat is higher than Vice Admiral so... hahaha j/k

Yes, they are both 2-cylinder, single carbed motors.

Anyone else have an opinion or additional information on the subject?

 

[ezeke]

Re: Is it better to drain the carb or not?

I'll put my 60 years at the school of hard knocks in here: You should fog your engine heavily with fogging oil and then drain the carburetor bowls by momentarily removing the plugs.

 

[Bard1]

Re: Is it better to drain the carb or not?

I'll put my 60 years at the school of hard knocks in here: You should fog your engine heavily with fogging oil and then drain the carburetor bowls by momentarily removing the plugs.

? Are you using the fogging oil only for long periods of down time or after each use

 

[Vic.S]

Re: Is it better to drain the carb or not?

I am in the running the carb dry camp.
I do it with my 6hp but not after every run. After a weekend sailing yes but not when it is going to be used again within a day or two and def not if it's going to be used again the same day.

Let it run out at idle speed, when its well over lubed anyway.

 

[DJ]

Re: Is it better to drain the carb or not?

This topic was beat to death here:

http://forums.iboats.com/showthread.php?t=287458

 

[samo_ott]

Re: Is it better to drain the carb or not?

Ok, so Chief of the Boat is higher than Vice Admiral so... hahaha j/k

Yes, they are both 2-cylinder, single carbed motors.

Anyone else have an opinion or additional information on the subject?

The big question is, how long is the engine not being used between run times? That will dictate the process.

 

[HybridMX6]

Re: Is it better to drain the carb or not?

Well, here's what I used to do, and will probably start doing next trip.
I used to run it dry, and it is a 2000 55hp 2 cyl, 2 carb motor. After rebuilding a 3cyl 60hp and seeing what happens when no lubrication is present in a cylinder, I think I'll be using Sta-Bil from now on and leaving it full. It's not really that expensive if you can find the larger bottles, and 1oz it says treats 2.5 gallons, so it's going to last me a while. I don't take my boat out all that often, I've been more into kayaking lately, or mountain biking, so it does sit for periods of time between uses, so I need to use Sta-Bil anyways.

 

[BSDenning]

Re: Is it better to drain the carb or not?

OK, I'm getting the consesus that with a 2 cylinder, single carbed motor, it is better to run the carb dry if it's not going to be used for a few weeks. If the motor is going to be used in a few days, there's no problem leaving the fuel in the carburator. But, to winterize, the best thing to do is to pull the plug, drain all the fuel and fog the cylinders and carburator.

By the way, when you say pull the plug, are you refurring to the small screw at the bottom of my carburator near the high speed adjustment needle (that's what I saw on the 1957 7.5 hp, I have not looked at the carb on the 10 hp yet)

 

[samo_ott]

Re: Is it better to drain the carb or not?

For a few weeks I wouldn't do anything personally. For a few months I would put some stabilizer in the fuel. I believe gas is good for 6 months or so... Or here up north for a season as the additives are vastly different in the winter and the summer in fuel I'm told when it's well below freezing...

 

[Gary H NC]

Re: Is it better to drain the carb or not?

The screw on the bottom of the carb will drain the bowl...it will empty the carb without running the cylinders dry...
We all have different opinions......

On my V6 motor i just run stabil through it and i'm done...never have drained the carbs for winter lay up...no problems yet...I guess i could go out and drain the bowls....

 

[ezeke]

Re: Is it better to drain the carb or not?

Fogging oil is injected into the carburetors before storage and as part of winterization to coat the cylinders, piston rings and bearings well and help to prevent rust from forming.

Specifically, each product will have instructions as to what to do and none of them say to add it to the main gas supply for fogging.

For example, on the SeaFoam label these words are printed:
"TO STORE AND FOG ENGINES, inject SeaFoam through carburetor and spark-plug holes, saturating internal parts."
I think that the operative word is saturating"

Draining the carburetor bowls after everything else is done will help to prevent the formation of gel in the bowls and high speed jets if storage is extended.