should I run fuel dry after used....

chippachap

Recruit
Joined
Jul 22, 2003
Messages
4
I just bought a 1995 115 mercury OB 2 stroke 4 cyl. The guy I bought it from told me that after he uses it he ran the fuel dry meaning taking off the fuel line and running it till it dies. My question is should I be doing this after every weekend of use? Is this helping the motor or could I be causing further problems? Any answers on this topic would be greatly appreciated..
 

fgbutler

Cadet
Joined
Jul 26, 2003
Messages
28
Re: should I run fuel dry after used....

If you take the boat out regularly you should not have to worry about "drying" out the carbs. If gas sits over long periods it breaks down leaving deposits in the carbs, junking them up. If left for extended periods (over winter) it may be a good idea to drain those. Also you can use additives to keep the gas from breaking down too early or too much.
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: should I run fuel dry after used....

This question will raise many views on Iboats and I was involved in a previous discussion with a similar subject. (Stale gas)<br />My interpretation of the best practice is:<br />Yes, run the carbs until the motor has revved up (leaning out) and is just about to die then shut it off and remove the line.This is supposed to enable just enough pre-mix to remain in the cylinder for lubrication.<br />Don't store the fuel for longer than 8 weeks(Merc shop manual) as it may begin to gum up after that. If you are using the boat weekly, just keep the fuel connected and the carbs full.
 

MurdockJr

Petty Officer 3rd Class
Joined
May 14, 2003
Messages
97
Re: should I run fuel dry after used....

This motor is 2+2 idles on 2 cylinders than kicks the other 2 in at around 2000rpm, so I dont think you could run the gas out of the bottom 2 carbs. The only way to drain the bottom carbs is manually, as they do not have an idle circuit. :)
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: should I run fuel dry after used....

Do a search on Mercury 2+2 in all open forums as there are quite a few posts about this motor.<br />It is apparently a 4 carb motor and a bit unusual, so it will obviously be different to my "run of the mill" 4 cyl 50.
 

The Marine Doctor

Commander
Joined
Jul 25, 2003
Messages
2,177
Re: should I run fuel dry after used....

Its not wise to run the engine out of fuel...instead us a fuel stabalizer. That way you will not risk any engine damage.<br /><br />Mercury sells Fuel conditioner...we use it to winterize boats...just follow the directions on the back for usage.<br /><br />TMD
 

jdkzrt

Petty Officer 3rd Class
Joined
May 26, 2003
Messages
83
Re: should I run fuel dry after used....

If the purpose of running the engine out of fuel (by disconnecting the gas line) is for storing the engine dry, you are wasting your time. Even when the engine stalls, there is enough gas left in the carb float bowls to gum them up completely.<br /> For winter storage, use fuel stabilizer, fog the engine and drain the float bowls.<br /> For weekend to weekend (or month to month) use, just drive it!
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: should I run fuel dry after used....

My personal preference is to start it up with fresh fuel at least every 4 weeks to keep any fuel left fresh and to keep it lubricated.<br />This is during the season where it cannot be used due to weather. :confused: :confused:
 
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