Somewhere near the front counter of nearly every automotive store. You will see a small red and white container of seafoam for $12 a bottle. As it turns out it is not a very complicated product and only consists of few ingredients. you can actually find the MSDS of seafoam online http://www.sueschauls.com/Seafoam_motor_treatment....
The ingredient are as follows:
40-60% Pail Oil: Deisel Fuel, Automatic transmission fluid, or a light motor oil.
10-20% IPA AKA: Isopropyl Alcohol
So now that you have you ingredients to make your own engine additive. You just have to mix them together and store them. Its easier to remember as the 4-2-1 method. 4 parts pail oil, 2 parts Napatha, 1 part Isopropyl Alcohol.
I just use a measuring cup and store in a 1 gal container. The measurements are as follows.
4 cups of diesel fuel
2 cups of the Napatha
1 cup of Isopropyl Alcohol.
When treating the fuel I use the seafoam dosage recommendations of 1oz per gallon. Just to be on the safe side. Now I do not claim this dosage or ingredients to be an exact replica of the seafoam brand itself. Im sure they have other additives, or blends added. I am going off of the MSDS sheets and from what I have learned through my research online. It is always better to be safe than sorry. I am not liable for any damages that may occur.