Re: Can you add Octain Booster to fuel on a outboard motor
Guess I have to say something, being it is "Almost an oil war"!<br /><br />The 85 HP Evenrude, (1975-77 vintage), which was mated to a 15 Ranger Bass Boat that I had back in the early eightys which I have made mention of before, I bought used. The previous owner was the original owner and he ran Leaded super in it from the beginning and recommended I do the same. He also ran Texaco 2 cycle oil all its previous life. At that time of my life, I probably wasnt the sharpest tack in the box so I didnt know any better.<br /><br />I imeadiatly started using the 100:1 Amsoil at about 80:1, didnt decarb, (Never even heard of it), and used Union 76 Leaded Super. It allways ran like a scalded cat. One time I went to fill up before a tournament and was about empty, the station was out of the Super, so I filled with regular. After I got out on the lake after a few minutes I could hear the difference in the engine, it was lounder and didnt sound as smooth. However, all that day it was just a bit faster, maybe 1-200 RPM from normal at WOT. The next time I filled up I filled with the super again and after running a bit, it smoothed out and was back to its normal self again.<br /><br />Now, with that said, There is the chance that this engine had become an octain junky do to some carbon buildup.<br /><br />The other thing I want to say to get back on topic is that when people put super in there boats after running them on regular for a while, I think that they will actually sound smoother due to the slower burn rate of the higher octain fuel. My Merc 150 is like that, it sounds noisier with 87 than it does with 91. That is before I started using the GTA fuel additive. Now it is quiet again.