I just recently switched oil to Motul 800 and wanted to experiment a little with different gas. This is something I noticed awhile back but never really concerned me until I read Brad's post on using a 395 carb....:msp_smile: While the saw runs fine, maybe the carb is showing it's age...maybe not which is why I ask.
When I have it tune for let's say...14.2-14.4K ish, when I run it up it quickly reaches and 4-strokes around 13.5-13.8K, then slowly builds to about 14.3-14.4 but seems to want to take about 4-5 seconds after it hits around 13.5K. The saw did this before on the Ultra so I'm fairly confident it's not the oil.
The saw has had some port work done but the muffler is still stock, maybe that's one reason...dunno.
When the L & H needle is set, and it holds a steady idle around 2500-2700, it bogs slightly off idle. Not a lot but almost like the sound of an old Q-jet....:msp_biggrin: From about 4K it's very snappy.
I don't think the carb has ever been touched so I'm contemplating trying the larger carb if it needs any attention.
The saw runs good on 89-93 but I guess I'm after the "sweet spot" now. Air filter is pretty clean, fuel lines are good.
On to my experiment...
I installed a fresh NGK plug, made a 50:1 pint of 91 octane and a pint of 93 octane just to compare. Tuned both tanks the same at WOT and using a 22" piece of hickory I was able to maintain about 11.3-11.5K on 3 cuts on the 91 and about 11.8 on the 93. I saw low 12's about 1/4 the way through but at the halfway mark it was just under averaging high 11K's
When I used the 91, I actually mixed it from some 87 and some 93 from the same pump, two separate containers and I dumped about 2 gallons in my car from each to clear the lines. What I did notice was a more yellow 93 and that concerned me. I don't know it this is because it's 93 or the fact 93 is just so expensive that it likely sits in the tanks longer, this fuel was taken from a busy station. If it's old then my test is botched for sure so hopefully 93 just has a different flavor.
Took a day off to let the leg rest so I had some free time. :msp_biggrin: And yes.....I wore the chaps. :msp_wink:
When I have it tune for let's say...14.2-14.4K ish, when I run it up it quickly reaches and 4-strokes around 13.5-13.8K, then slowly builds to about 14.3-14.4 but seems to want to take about 4-5 seconds after it hits around 13.5K. The saw did this before on the Ultra so I'm fairly confident it's not the oil.
The saw has had some port work done but the muffler is still stock, maybe that's one reason...dunno.
When the L & H needle is set, and it holds a steady idle around 2500-2700, it bogs slightly off idle. Not a lot but almost like the sound of an old Q-jet....:msp_biggrin: From about 4K it's very snappy.
I don't think the carb has ever been touched so I'm contemplating trying the larger carb if it needs any attention.
The saw runs good on 89-93 but I guess I'm after the "sweet spot" now. Air filter is pretty clean, fuel lines are good.
On to my experiment...
I installed a fresh NGK plug, made a 50:1 pint of 91 octane and a pint of 93 octane just to compare. Tuned both tanks the same at WOT and using a 22" piece of hickory I was able to maintain about 11.3-11.5K on 3 cuts on the 91 and about 11.8 on the 93. I saw low 12's about 1/4 the way through but at the halfway mark it was just under averaging high 11K's
When I used the 91, I actually mixed it from some 87 and some 93 from the same pump, two separate containers and I dumped about 2 gallons in my car from each to clear the lines. What I did notice was a more yellow 93 and that concerned me. I don't know it this is because it's 93 or the fact 93 is just so expensive that it likely sits in the tanks longer, this fuel was taken from a busy station. If it's old then my test is botched for sure so hopefully 93 just has a different flavor.
Took a day off to let the leg rest so I had some free time. :msp_biggrin: And yes.....I wore the chaps. :msp_wink:
....372xp.
