Break in time for a 365 ?

[Madman Mark]

Hey all, this is my first time here (be gentle).
I bought a new 365 last week and have put 5 tanks of gas through it so far, works great.
The manual says to put 8-10 tanks through it before retuning, but the guy at the shop said to put 40 hours on it.
There's no need to put that much time on it, is there ?
Also what are some opinions on this saw ?
I use it mostly to block hardwood, 1 or 2 cords a week and I find it perfect for that with an 18 inch bar and 3/8 chain (good balance,power etc..).

 

[Stumper]

I'd go with the manual. You'll probably have room to tweak it again at 40 hours but most of the 'wear-in' should take place in those first 5-6 hours.

 

[Crofter]

You may not have to do anything to it at all. Did you set the carb yourself or is it as you got it from the dealer. It is customary to set it a bit on the rich side for a breakin period so it is possible it may handle a bit of leaning out after it breaks in, but dont lean it out if it doesnt need it! TOO LEAN A MIXTURE is close to number 1 cause of frying a saw. The 365 is a very user friendly saw but it is not noted for being a real high revver so dont let anyone talk you into tweaking it that way. My 365 definitely cuts faster times when set a bit on the rich side.

Frank

 

[Madman Mark]

The guy at the shop set it for me.
He set the max rpm at 12,500 and said to put 40 hours on it then bring it back.
I've had a few new saws over the years (mostly Husqvarna) and was never told to break it in for that long.
I only ever adjust the idle (not on this one yet) and leave the rest for them.

 

[bwalker]

When my 7900 gets here I am going to start it up, let it come up to operating temps and then shut it off and let it cool completly. After going through the heat cycle process I described above I am going to warm it up set the carb to the reccomended max no load rpm and run it like I stole it. Two cycles require little no break in becase they use ball bearings. The only thing that needs to be seated is the cylinder to ring interface and this is only accomplished by high load and rpm. BTW I do not use any special break in oil or anyhting. Mobil mx2t and amoco premium at 32:1.

 

[Crofter]

"Two cycles require little no break in becase they use ball bearings. The only thing that needs to be seated is the cylinder to ring interface and this is only accomplished by high load and rpm."

Ben I agree about the lower end not being critical for break in and also about full load putting the pressure on the rings to seat them. I do think though there is some benefit in running a rich mixture for 5 or 6 tanks of fuel for the following reason. A leaner mixture will result in a higher piston temperature and tighter fit in the bore. There is always some micro irregularities in machining finish that will smooth out some with a few hours running and this will be a bit more "relaxed" with a richer mixture. A well experienced 2 stroke will stand a better chance at surviving a lean run than a squeaky new one!
I really don't know what the benefit is of running a number of tanks thru at idle before powering up as some recommend. To me that is the extreme in the other direction.
It sounds like the dealer has set your saw up a bit on the rich side for safety but I think 40 hours is more time than you need to consider it broken in. It is a good thing not to monkey with the carb if you don't know how to set it, however there are other things that can happen to a saw to make it run lean and if you don't recognise the symptoms you could fry your saw. Learn how to adjust the carb even if you don't plan on monkeying with it

Frank

 

[bwalker]

I really don't know what the benefit is of running a number of tanks thru at idle before powering up as some recommend. To me that is the extreme in the other direction.

The only thing this practice does IMO is increase the chances of glazing the cylinder, and either never getting a good seal or prolong the seat-in time longer than neccesarry. BTW Crofter I dont advocate running a lean mix. I have found that the no load spec of factory saws is usually on the safe side.