Best fuel system cleaner for outboard motor?

[SecondMonkey]

I have a 1972 150hp Mercury outboard that I rebuilt and restored 2 years ago. Since then, it's sat a lot, with gas always aging in the carbs. It still runs fine, but one of the carbs is leaking a little - and that's what it does when they get sticky.

Anyway, what would be the best fuel system cleaner to use in this 2 cycle motor? Are there things that would be damaging to a 2 cycle? How 'bout Chevron's Techron additive?

 

[mikeg5]

i know that a lot of guys use seafoam. the best thing for you to do honestly is to take the carb off and hand clean it and reinstall... use the seafoam (as per directions on the bottle) to keep the stuff from coming back.. one more tip, if you are running high test gas (93octane), switch to 87, for some reason they run better and mix with seafoam

 

[Turk]

Ditto.

 

[dwendt44]

Why is it leaking?
Bad gasket, or bad float?

 

[NHHEMI]

Actually, if you want the best fuel system additive( cleans and stabilizes )for your outboard then find some OMC 2+4. I have tried other similar products from other marine mfg's but NONE came close to 2+4. I have also found automotive products do not work as well in 2-stroke OB's as marine specific ones do. Probably due to the 2 cycle oil. 2+4 works amazing on 2-stroke OB's and also 4-stroke OB's, yard equipment, 2 cycle motorcycles, etc...

This stuff here...
http://theoutboardwizard.bizhosting.com/_775613_8oz_2_plus_4_fuel_conditioner.html

This stuff is nothing short of a miracle in a bottle. Add a good dose to your gas tank( add like 1/4 bottle the 1st time - won't hurt adding more )and I swear within 5 minutes, 10 tops if the carb's are really nasty, it will clear it out and have it running like new( if a rebuild is not needed due to faulty parts not just that it is gummed up - you may need to change plugs before and after just FYI ).

I run it in all my OB's. I used to run nothing but Evinrude 2-strokes and it kept them running like new. Another suggestion I will make is to use a synthetic 2 cycle oil. I had very good luck with Cabela's brand. Much less smoke and it did not gum the carbs or foul the plugs anywhere near as bad. Not even when running the motor in Jan and Feb duck hunting.

Cabelas TC-W3 Synthetic( semi/blend )2 Cycle Oil...
http://www.cabelas.com/cabelas/en/templa...0061&hasJS=true

I also use the 2+4 in my lawn mower, snow blower, and weed whackers. It is amazing how when something runs rough or stalls out you add some 2+4 and you can watch and see how literally it smoothes the idle out as it cleans in no time. I have one of those cheap 2 cycle WW's. The kind you throw away every year because regardless of how you prep them for winter storage the carbs always gum or varnish up and they never run right after that 1st year. The 2+4 fixes it in less than a minute and it runs like new each spring.

2+4 is really something in 2 cycle engines.