Decarb/Ringfree Options
 

On my 1978 23' SeaCraft SF I have twin 1998 Yamaha's. Supposedly (according to the last owner) they have about 600 hours.

I have taken out the boat twice over the past week for about hour long cruises. Both times when the engines were cold they took a number of cranks before they would cooperate. Once they were running they seemed fine.

High end speed is in a little more than 40 (at aroung 5200+ RPM's). Compression is very similar on both engines (127 to 140) on each engine.

I am thinking that a good decarb might help things out a little. On my prvious boat (which had a 175 HP 1997 Johnson Ocean Runner) I would shoot the decarb down the carb throats, as well as into each of the cylinders.

I have been doing a little research and have been coming across the following options.

1. Use Seafoam in a small gas tank (along with gas and oil)
2. Use Deep Creep like I used to use decarb on my old Johnson (no jokes please!)
3. Use Ring Free
4. Use the old decarb treatment.


I would appreciate any insights that my highly esteemed fellow ClassSeaCraft members may have.

Thanks

Re: Decarb/Ringfree Options
 

Peter - Are you trying to clean the carbs or combustion chamber? I run ring free on just about every fill up on my OX-66 250 Yam (constant treat).

In order to "shock" treat larger V-6 outboards with ring free requires 2 oz/gallon and something like 60 gallons of fuel for the V-6ers (each in your case).
You would need about 240oz and treat/run 120 gallons of fuel.
Pretty expensive option considering ring free around here is about $24.00 for 32oz bottle.

Curious to see what others say..
FishJack

Re: Decarb/Ringfree Options
 

I use Ring Free 1 oz per 10 gal. For your needs I would first use the Shock treatment of Ring Free and then add along with you gas at fill ups.
FellowShip [img]/images/graemlins/wink.gif[/img]

Re: Decarb/Ringfree Options
 

If you can easily get to the carbs, I'd go with the Deep Creep. It's the easiest. Otherwise use the Seafoam/small tank solution. I use that stuff, or similar in everything from weed trimmers to outboards. Once a year treatment really helped my 1973 115 Johnson that I owned until 2002. The first use made the biggest difference.

Re: Decarb/Ringfree Options
 

Peter-

On my old boat i had twin 1999 Yamaha 200's same block as your 150's. Great engines by the way.

Yamaha offers a decarb solution in a spray can and i used that for the decarb. By would I smoke out the neighborhood!!!

I forget the name but you take off the front air shield and spray it right in the carbs.

Re: Decarb/Ringfree Options
 

here is a pic of the yamaha "snake oil"

http://www.yamaha-motor.com/assets/a...-CL-NR-500.jpg

Re: Decarb/Ringfree Options
 

Another option in "Powertune" from Mercury Marine. It's hard to find in bulk quantity, but running the engine in the water (not on the hose) and spraying it down the intake will clean out an amazing amount of carbon. And yes, it makes a whole lot of smoke.
A local marine distributor here in FL sells the Powertune in bulk for $35 a gallon. I usually put 8 ounces into 25 gallons of fuel. Shine a light into my cylinders and they're shiny clean, as are the plugs.
OH YEAH, if you shock your engine with Ring Free or some equivalent, change your spark plugs after. Trust me on this. [img]/images/graemlins/smile.gif[/img]