Originally Posted by
w8ye
On gasoline the exhaust will be mostly dry smut.
But what comes out the crankcase vent will look like diesel engine crankcase oil that has a 100,000 miles on it. It will be black syrup.
You should be running a 16 - 20 to one (16:1) ratio to not have a rod failure.
+1 - 16:1 Gas/Oil ratio is the minimum you want to run-in a plain conrod bearings 4 stroke engine, after run-in you can go to 20:1 on the larger engines, but on a 15cc (.91) a 16:1 is always the magic ratio. I use this ratio for all 2 and 4 strokes conversions above 10cc (.61), it may be a bit high of a ratio for my ASP180's but rather be safe than sorry! Some would say that lower oil ratios gives you more power, this is incorrect in most cases!