Kenskip1
Super OPE Member
- Local time
- 9:11 AM
- User ID
- 642
- Joined
- Jan 21, 2016
- Messages
- 146
- Reaction score
- 272
- Location
- Waynesville, Missouri
So, here's what not happening. My 590 saw is just over a year old. When I got it I was using 87 octane with Amsoil at 40/1 The saw ran perfect with no hesitation what so ever. So after reading the owners manual it says 90 octane or better. So with the 91 and the same oil and ration the saw has developed a slight hesitation from idle. I have richened the mixture on the low side with the same results. My air filer is clean as is the gas filter. I am wondering if the 91 octane that has a higher flash point could be the cause. The 87 has a lower flash point and is easier to ignite. Am I barking up the wrong tree here? Otherwise the saw is perfect. Oils good and has plenty of grunt pulling a 20 B/C through oak. I just dislike the hesitation. BTW it has 175 pounds of compression. The muffler has been modified from the day I purchased it. Thanks, Ken