Is the alcohol keeping my motor clean?

[surlyjoe]

MY '60 Evinrude big twin seems to have almost no carbon build up when doing de-carb. This is the first new (as in fully rebuilt ) motor I have ever run, but I am used to seeing the carbon coming out the back and at least some black on the sheet of plywood I use as a deflector to keep the water out of the garage. We run twice a week 6-8 gallons at a time with West Marine cheapo oil , bout half running and half jumping holes. I figure maybe 400 hours since rebuild and this is the first one. I used the OMC stuff, the whole can and let it set 12 hrs. whats up?


BTW, whatch out for your seals with this new gas, everything old school gets all swollen up and gooey. =(

 

[WillyBWright]

Re: Is the alcohol keeping my motor clean?

Alcohol makes more carbon than gas, so alcohol blended gas will make more carbon than straight gas. Unleaded gas makes less carbon than leaded gas did. TCW-3 oil contains additives that prevent carbon from sticking to surfaces. So compared to what that motor started out with, carboning is reduced very very substantially. I'd guess using modern products leaves no more than 20% of what used to be left back in the 60s.