Do I need to re-tune with a 42" bar on the saw?

[mogman8]

I'm fairly new to this site and new to larger bars and plan to do some milling in the future but for tomorrow I plan to just be cross cutting some sections of a 60" willow tree with a brand new cross cutting chain with a Husky 272xp. This is the first time I will run the saw with a 42" bar on it. Do I need to re-tune with the large bar on the saw or should my tune be good from when I had the 20" bar on? I read some suggest running richer or higher oil ratios for milling jobs, what are your thoughts and if you agree, how much richer or when tuning, what do you do beyond listening for the four stroking sound as you would in a "normal" tune? Outside temps will be about 32 degrees.
I have Homelite premium oil and Pro Mix premium oil in my garage that both specify 2.6 oz oil per gallon and mentions nothing about actual ratios. Do I need to go get another oil or will this be fine? Whatever oil you recommend, I would hope is readily available since I plan to do this tomorrow afternoon. I will be using 93 octane fuel and despite what everyone says about not running ethanol, I have no choice here in the People's Republic of mASSachusetts. Thanks for your help!

 

[SDB777]

The only thing I do for longer bars is increase the amount of oil going to the bar.....

Scott (re-tuning sucks) B

 

[BobL]

I'm fairly new to this site and new to larger bars and plan to do some milling in the future but for tomorrow I plan to just be cross cutting some sections of a 60" willow tree with a brand new cross cutting chain with a Husky 272xp. This is the first time I will run the saw with a 42" bar on it. Do I need to re-tune with the large bar on the saw

NO.

or should my tune be good from when I had the 20" bar on?

YES

I read some suggest running richer or higher oil ratios for milling jobs, what are your thoughts and if you agree, how much richer or when tuning,

Another incorrect use of the term richness.
Richness when tuning refers to the MIX to AIR ratio and has nothing to do with the GAS to OIL ratiol in the mix.

what do you do beyond listening for the four stroking sound as you would in a "normal" tune? Outside temps will be about 32 degrees.

I tune the saw 500 rpm below spec using a tach for milling. I don't bother to retune for cross cutting because I have separate saws for this. I'd probably retune if it was for more than one log worth of crosscutting.

I have Homelite premium oil and Pro Mix premium oil in my garage that both specify 2.6 oz oil per gallon and mentions nothing about actual ratios. Do I need to go get another oil or will this be fine?

I don't know these oils but I would recommend using whatever the user manual says for the gas to oil ratio.

 

[mogman8]

I do understand the difference between a richly tuned carburetor and gas to oil ratios, it was a two part question meaning should I tune the carburetor richer AND OR run a higher gas oil ratio. I gather from what you said that I should tune the carb a little rich to lower the top rpm's but run the manufacturers recommended gas to oil ratio with a high quality oil.

 

[BobL]

I do understand the difference between a richly tuned carburetor and gas to oil ratios, it was a two part question meaning should I tune the carburetor richer AND OR run a higher gas oil ratio. I gather from what you said that I should tune the carb a little rich to lower the top rpm's but run the manufacturers recommended gas to oil ratio with a high quality oil.

Yep - all good.