Sorry, I know this decarb horse has been beat to death, but...<br /><br />Does the smoke plume indicate that there's still carbon being removed, or will Seafoam cause smoking even in a carbon-free engine? I ran about 1.5 gallons of gas/seafoam through (at 1 can seafoam per gallon of gas. I put it on a pony tank with the mix. Let her high-idle (on the hose) for 10 minutes or so, shut down 15 minutes, started back up, revved a couple of times, and repeated the process...about 10 times... I don't think the amount of smoke changed much each time. I took it to the lake and ran it a while -- Didn't notice any obvious difference. Pulled the plugs later. They looked a little better, but when I shined a light on the pistons, they still looked pretty carbed up on top.<br /><br />Which brings me to question 2: Does anyone put seafoam in a spray bottle and spray it (undiluted)through the plug holes? Would this be more effective? And if so, is there any potential for problems? How long should I let it soak in the cylinders? (Guess that was more than 1 question!)<br /><br />By the way, the motor ('87 Yamaha) runs well but idles a little rough. I bought it recently from the 2nd owner, so I don't have much history. I know it hasn't been used on a regular basis the past few years, but 1st owner had a pretty good trolling setup, so I was concerned about carbon.
