DO switch from the Ashless you are running. But also DO follow what PlaneKrazee says regarding the mixture between 32:1-50:1 (32-40:1 for regular oils, 40-50:1 for synthetics). I personally use Pennzoil at 32:1 in everything. It is readily available to me, inexpensive, I buy it by the case. My synthetic choice would be Stihl Ultra from the local small engine shop, but unless the Pennzoil is suddenly unavailable or inconvenient for me to get, I won't be moving to it. I'd just encourage you to avoid the temptation of going to a popular oil that is mixed thinner than 50:1...though there are many followers. Save your money, and use something else...in the long run your engine will appreciate it.