SeaFoam question

[EX-YANK]

One of the suggested use from seafoam is to add to the crank case oil ( 1/2 pint per 5 quarts of oil). I am planning on doing an oil change soon on my engines ( 1996 Crusader 350XL) and thinking to adding this treatment, take the boat out for an hour cruise then perform the oil change.

Is it okay to add this to the crank case as seafoam suggets, and how many hours should I put on the engines in order for the seafoam to do its job?

Any negatives, or bad things that could happen?

[Bob H.]

Drive gently for a 1/2 hour or so and change the oil.

[Capt Kid]

yamaha makes a gret product called ringfree that is safe for all 4 strokes including inboards and land vehicles that goes in the crankcase and run high rpm for about 30 min and change oil supposed to get rid of carbon and sludge

[brian v. bashara]

Sea foam has been very good to me in my Duramax,lawn equipment,Yamaha also used Full Throttle.Would like to equally know about this product(Sea Foam) as I am a believer,why should I be?

[hippie]

A marine engine seldom loads up with "sludge". Due to the high rpms, the engines are usually clean. Bob

[CaptBeach]

Is RingFree or SeaFoam really Marvels Mystery Oil repackaged and sold at 3-4 times the price? Anyone ever use Marvels Mystery Oil in there IB/OB engines?

[WildeOne]

SeaFoam is not Marvel ... it's typical use is for decarbonizing two stroke motors. All you have to do is smell it and you'll know it's not any kind of oil at all. Never have used MMO in any outboard and never will.
Jim

[Hampton]

Whoa there Capt Kid. You do NOT put Ring Free in the crankcase. It is designed to go in your fuel tank. DO NOT PUT IT IN YOU CRANKCASE! They do request that you change your engine oil after "shocking" the system by using double the usual amount. There are better products out there than Ring Free for removing and reducing the carbon in your engine.