Injection or pre-mix?
I'm going to throw a wrench right in the works. How about both? I haven't always done this, but have just tried it lately. Lemme try to explain. Bike; 77 Yamaha DT400. Top end refresh. I found everything in good shape when I opened it up. Complete de-carbon, light cylinder hone, reassembled with original, first size piston, new rings and gaskets. Knowing I would be breaking in and riding this bike in the winter, I went one size larger on the pilot jet and raised the main jet needle one notch. So, I figured since it's running little richer, and I wanted to give it a couple easy heat cycles, I put a gallon of 70:1 pre-mix in the tank and ran it out. A little smokey at idle, but, once warmed up and blown out, seemed to be ok. Then it snowed. I needed to get the snow blower running. So, I poured last years 50:1 stale sludge into the tank and went out and burned that off. Again, seemed ok. My question to the collective is this. With the carb jetted richer for cold conditions, is it necessary, or at least a good idea to add the 70:1 to compensate. (the oil injection pump is operating at stock setting) Or am I just wasting oil and adding excess carbon to my now clean top end? Has anyone else ever done this? I have not pulled the plug yet for a look-see, but will report back when I do. Whadda U think?