I was going to start a new thread on this, but what the heck.
I mixed up a batch of fresh no name regular with ethanol (87 octane), with Amsoil Dominator (racing oil) and pure castor oil a little over a month ago. Nice blend, bike went like a moose seeking love. I went through 2 partial tanks on my bike. I left about 3/8 to 1/2 gallon in a plastic gallon can sitting…….I ran my tank very near dry….so Saturday I filled the tank near full. After a few runs up and down my block demo-ing my bike and such with Ghost0, my bike started to run a little funky - I thought it was the expansion pipe I had just shortened! (Tricky - see separate thread). We rode a bit further and my bike was REALLY running like dog stuff smells. So I lengthened my pipe back up and it ran marginally better, but not much…..let it cool down, check the plug (yeah basics first
) and spanning the electrode gap is a big nasty black stringer.
So after reading this thread I suspected my fuel (and the castor) - I drained the fuel (put it in my car, drove a bunch since, no problems). I made a hearty mix of fuel, Dominator and NO castor. Wound in a brand new properly gapped NGK B6HS. Bike started right up, ran a little rough at first, but as the old fuel left the carb bowl (yes I should have drained it!!) the bike just started to run better and better and better…..problem solved.
Old fuel with ethanol and castor is not something you want in your engine. Up to 10% ethanol gasoline will work with castor and synthetic oil, if you mix and use it on the spot, but please don't store it.