550XP mark 2 / 572 fuel mixture with pipe

[Sean2202]

Greetings,

Picked up these two saws over winter, great overall saws. 550 has 18" bar and 572 has 24". I have run about 5-6 tanks of fuel through the 550 and only about 1 through the 572. I have been using 50:1 ratio as the dealer suggested. Echo power blend oil. 89 octane fuel unfortunately with ethanol as non-ethanol is not available unless I buy the canned fuel from the dealer. I just added a pipe to the 550 and have one on order for the 572 from chainsawperformanceparts.

What I have been reading lately and would like to verify that some people suggest running a richer mixture on these saws of 40:1 or even 32:1 because of the speed they run at and to extend the life of the saw. What are the overall thoughts on this fuel mixture change or changing the mixture after adding a pipe to the saw. I also added a single air vent to the air cleaner cover on the 550 and am considering doing the same on the 572. Should I change any of the above oil, fuel or mixture that I have been using?

I have also read that the pipe keeps the saw running cooler? Possibly extending the life of the saw? These two saws are just for use around the farm and for fun. I would like them to last a very long time.

Thanks for any suggestions.
Sean

 

[Squareground3691]

Greetings,

Picked up these two saws over winter, great overall saws. 550 has 18" bar and 572 has 24". I have run about 5-6 tanks of fuel through the 550 and only about 1 through the 572. I have been using 50:1 ratio as the dealer suggested. Echo power blend oil. 89 octane fuel unfortunately with ethanol as non-ethanol is not available unless I buy the canned fuel from the dealer. I just added a pipe to the 550 and have one on order for the 572 from chainsawperformanceparts.

What I have been reading lately and would like to verify that some people suggest running a richer mixture on these saws of 40:1 or even 32:1 because of the speed they run at and to extend the life of the saw. What are the overall thoughts on this fuel mixture change or changing the mixture after adding a pipe to the saw. I also added a single air vent to the air cleaner cover on the 550 and am considering doing the same on the 572. Should I change any of the above oil, fuel or mixture that I have been using?

I have also read that the pipe keeps the saw running cooler? Possibly extending the life of the saw? These two saws are just for use around the farm and for fun. I would like them to last a very long time.

Thanks for any suggestions.
Sean

Yea , I always duel port my mufflers for better flow and cooler running saw, 550 is a must for better performance, they are to restricted from factory, here’s the 550 with extra port ,

 

[NSEric]

Two of my buddies have 550's, none of us run 50-1, we all run 32-1 in our saws, without issues.
The auto tune saws like a little extra oil because they run boarder line too lean all the time.

How loud is your pipe?
I dont like 9/10 pipes because they're so loud, A simple muffler mod is better IMO.

 

[buzz sawyer]

32:1 is leaner than 50:1. More oil, less fiuel. OK as long as you tune for it.

 

[NSEric]

32:1 is leaner than 50:1. More oil, less fiuel. OK as long as you tune for it.

We're talking about auto tune saws, they retune for the mixture change on their own.

 

[Squareground3691]

32:1 is leaner than 50:1. More oil, less fiuel. OK as long as you tune for it.

550 are Auto Tuned ,

 

[Squareground3691]

Two of my buddies have 550's, none of us run 50-1, we all run 32-1 in our saws, without issues.
The auto tune saws like a little extra oil because they run boarder line too lean all the time.

How loud is your pipe?
I dont like 9/10 pipes because they're so loud, A simple muffler mod is better IMO.

Not loud , went with 1/2 ID pipe 5/8 OD , also opened up factory a little to , put frog skins air vents in air filter box , breathes better to more are ,

 

[Sean2202]

Thanks for the replies and info. 32:1 mixture is not a problem because I usually have some on hand for my pro Mac 10-10. Once again with 89 pump gas (10% ethanol Exxon Mobil) and echo power blend oil) I assume the 572 could also benefit from using this. Thanks.

As far as the pipe goes it is pretty loud but I like it. If I did two full tanks in one session that would be a lot. Graduated from loud pipes from the daily driver but can’t seem to let it go yet with the toys.

 

[Sean2202]

One other interesting thing. I was at my local Husqvarna dealer recently which has been in business a long time and I asked what I should run for mixture and was told all husky saws have run 50:1 “for quite some time now.”

I run my older Jonsered 455 at 40:1 and just assumed all Husqvarna saws ran at 40:1. All my Echo stuff I run at 50:1 without issues.

 

[Squareground3691]

One other interesting thing. I was at my local Husqvarna dealer recently which has been in business a long time and I asked what I should run for mixture and was told all husky saws have run 50:1 “for quite some time now.”

I run my older Jonsered 455 at 40:1 and just assumed all Husqvarna saws ran at 40:1. All my Echo stuff I run at 50:1 without issues.

They do that as Husqvarna mandates the 50:1 ratios for economy and EPA standards, I run 40:1 and 32:1 in my saws , my ported saws and older Mcculloch’s and Pioneers , get the 32:1 treatment,

 

[Squareground3691]

One other interesting thing. I was at my local Husqvarna dealer recently which has been in business a long time and I asked what I should run for mixture and was told all husky saws have run 50:1 “for quite some time now.”

I run my older Jonsered 455 at 40:1 and just assumed all Husqvarna saws ran at 40:1. All my Echo stuff I run at 50:1 without issues.

Husqvarna isn’t looking out for the longevity of internals like bearings and such with 50:1 ratios , especially if you’re working the **** !! out of ur saws ,

 

[Tomos770]

One other interesting thing. I was at my local Husqvarna dealer recently which has been in business a long time and I asked what I should run for mixture and was told all husky saws have run 50:1 “for quite some time now.”

I have the same expirience with my dealer...
You can Imagine how his eyes rolled when I explained to him that I will be using 32:1 due to better longitivity of main bearings....

He started with story how nowadays oils (some) can be used even @100:1.....

And that was a part where I started to smile And luckily also where another customer came in the shop.....and ended our scientific conversation...

 

[Sean2202]

Thanks for all the replies and info. Good stuff. I will be sure to run my 550 and 572 with a 32:1 mixture from now on.

 

[huskihl]

It’s not so much the Autotune running lean, it’s that the whole 5 series are stratocharged engines. Due to the air passage cutouts in the piston, the pistons are heavier. Heavy pistons are hard on crank and case bearings. On top of that, rather than purging spent exhaust with a portion of fresh charge, they’re purged with fresh strato air. That fresh air never contained fuel and oil that would have otherwise lubed and cooled the bearings in a pre-strato motor. About 20-30% less oil goes through the crankcase on a strato than on a conventional 2 stroke.
Both of those are reasons to run more oil in the mix.

 

[ballisticdoughnut]

I’ve been running 40:1 mix in my 545 MkII since day one. Autotune will adjust to any variance in oil ratio no problem.

 

[Sean2202]

It’s not so much the Autotune running lean, it’s that the whole 5 series are stratocharged engines. Due to the air passage cutouts in the piston, the pistons are heavier. Heavy pistons are hard on crank and case bearings. On top of that, rather than purging spent exhaust with a portion of fresh charge, they’re purged with fresh strato air. That fresh air never contained fuel and oil that would have otherwise lubed and cooled the bearings in a pre-strato motor. About 20-30% less oil goes through the crankcase on a strato than on a conventional 2 stroke.
Both of those are reasons to run more oil in the mix.

Thanks for the explanation. I have read that these were "stratocharged", and I didn't really understand what that meant.

So, are some of these reasons why I have heard some pros prefer the 372 over the 572? I assume this series is different.

We have an old 353 at work. Used and abused. Thought it was dead. Got it running last year and seems to be good. The 550 goes through fuel a lot faster and cutting speed seems much higher. The 353 has had 50:1 its whole life. Stock form. Good saw.

 

[huskihl]

Thanks for the explanation. I have read that these were "stratocharged", and I didn't really understand what that meant.

So, are some of these reasons why I have heard some pros prefer the 372 over the 572? I assume this series is different.

We have an old 353 at work. Used and abused. Thought it was dead. Got it running last year and seems to be good. The 550 goes through fuel a lot faster and cutting speed seems much higher. The 353 has had 50:1 its whole life. Stock form. Good saw.

The original 372 was old skool, the newer 372 is strato, and the 572 is strato with Autotune. Lots of guys loved the original 372 and swore off everything produced after. The xtorq 372 and 572 both are a bit hard on bearings. To me, the 572 is much more ergonomic to run. Very smooth

353 was old school, 550 is strato (xtorq)

 

[Sean2202]

The original 372 was old skool, the newer 372 is strato,

So do all Husky saws that say "Xtorq" are strato and thus require more oil in the mix?

 

[huskihl]

So do all Husky saws that say "Xtorq" are strato and thus require more oil in the mix?

All saws that say xtorq are strato, yes. Whether you opt to add more oil to the mix for them is up to you. My experience with them says that you should.

 

[Tomos770]

Am I reading/understanding that right?

Husqvarna re-visioned main crank bearings (and some other stuff around them) on 550xp mk2 recently? Due to better longitivity....

https://www.husqvarna.com/us/suppor...6F8-4A60-B48E-D4514D026B51}&q=550 XP® Mark II