carbon problem

[beckarae]

I have a 2000 200hp 2 stroke injected yami. I have been fouling spark plugs, I have pulled the heads and there is exesive carbon on the pistons, cumbustion chamber and in the exaust ports. I am able to clean the pistons and the cumbustion chamber but I am cocerned about chiping carbon in the exaust ports for fear of where the carbon chips will go (in the exaust) I have thought about a vacume running while chiping away or air pressure blowing back threw the prop.
another question is the use of seafoam. I poored some seafoam in my cylinder head and it does not seem to have any affect on the hard carbon. I am also wondering the effects of a "hot shot treatment" with 16 oz. in one gallon of premix to do a hard clean. is this safe?

[robert graham]

Maybe run a couple of tanks of gas with the Ringfree "deposit removal" dosage of 2 ounces of Ringfree per gallon of gas. You may foul a few plugs while the decarbon process is working. Use Ringfree at the "deposit prevention" dosage of 1 ounce per 10 gallons of gas all the time thereafter. I use the Pennzoil 100% Synthetic outboard motor oil and it seems to produce less smoke and carbon. I wonder if your cylinder compression readings are low, indicating carbon stuck piston rings? Good Luck!

[poengine33]

I have used seafoam as a shock treatment which removes the carbon buildup in fact the amount of carbon that came out the exhaust at the prop was scary,,The carbon ooze out for 2 days and left a blob on the driveway that was the size of a small pizza ..In a portable tank mix one can of seafoam to 3/4 gal of gas and the oil mix run the motor for 20 mins then let set for 30 mins continue till all the gas is gone then weit the black mess will slowlly ooz out also when you do the treatment pick a winding day because you will smoke up the naborhood....

[poengine33]

I have used seafoam as a shock treatment which removes the carbon buildup in fact the amount of carbon that came out the exhaust at the prop was scary,,The carbon ooze out for 2 days and left a blob on the driveway that was the size of a small pizza ..In a portable tank mix one can of seafoam to 3/4 gal of gas and the oil mix run the motor for 20 mins then let set for 30 mins continue till all the gas is gone then wait, the black mess will slowlly ooz out also when you do the treatment pick a winding day because you will smoke up the naborhood....ps if you have a nice driveway put down a pice of plywood

[jonp]

Funny, I been using seafoam for a long time. Doing shock treatments every season, usually 3 or 4 X what is suggested in several gallons gas. I always did this while running in the lake never in the driveway. Engine just will not get enough water long term with muffs. I recently purchased a rescue 4.5 HP kicker for my 17 whaler. I ran a very high dose of seafoam in it for several hours in a tank. The amount black goo that came out of this little sucker was astounding. And it keep leaking for days just on the stand...