2-cycle engine break-in?

[Quattro Pete]

I was just reading instructions for a Stihl trimmer that I picked up... they actually mention to not run the engine at full throttle for the first three tanks.

That got me thinking, in a 2-cycle engine using gas-oil mix, what happens to break-in debris/wear? Does it just get dispersed through the exhaust?

 

[dwendt44]

Yup!

 

[ksJoe]

Some recommend using extra oil in the gas during the breakin.

 

[demarpaint]

I always added a little extra oil to the gas and took it easy for the first few tankfuls. I've had good luck running my 2 cycle engines in that way.

 

[dave123]

I think the manual would read no load WOT for first three tanks of gas. I always run Sthil 2 stroke power equipment WOT always under load from the get go and for the rest of it's life.

 

[Quattro Pete]

Yes, it says no WOT under no load.

 

[dave123]

Yes like I said big difference from WOT load and no load

With that said use it like you would any time of it's life. If you would see how I treat my Sthil saws and trimmers you might cringe but they run and run like the day I bought them.

 

[Fatboymoe]

When I get a new 2 stroke yard equipment machine, I always heat cycle it 4 to 5 times before I use it. No WOT, just vary the RPM's for a couple of minutes until hot then let it cool completely. I really don't know if it does any good, but I never have had any problems so far.

Most new 2 cycle engines call for a 50-1 fuel-oil mix. I use 40-1 for the first couple of tank fulls, then use 50-1.

 

[ksJoe]

Do you think 50:1 really provides optimal protection, or is that the result of pressure from the EPA?

 

[StevieC]

It's a balance of pollution, protection, and fouling in the engine. Depends on the oil, the additives in the oil, the engine you are using it in, and the additives in the fuel.

Each machine is different IMO!

 

[tom slick]

Originally Posted By: ksJoe
Do you think 50:1 really provides optimal protection, or is that the result of pressure from the EPA?


I think it is an evolution of oil quality.

 

[steve20]

my Echo blower (model P251) is one of the best peices of OPE I have ever used. Their sample oil bottle that came with it was semi-synthetic FWIW.
I have 4 year supply of the old Mobil Synthetic 2 cycle mix that I have been using-virtually no smoke

 

[Brons2]

I used 32:1 on my first couple of tanks on the chainsaw, runs good.

 

[ksJoe]

Originally Posted By: tom slick
Originally Posted By: ksJoe
Do you think 50:1 really provides optimal protection, or is that the result of pressure from the EPA?


I think it is an evolution of oil quality.


That makes sense.

Still, when I'm mixing fuel, I make sure if there is any error in my mixing its slightly strong instead of slightly weak. I'd rather risk the spark plug than the rings & bearings...

 

[Pete591]

Break it in with Amsoil Sabre' Professional Synthetic and always use 50:1.

 

[dwendt44]

My Lawn-Boy was designed to run on 32:1. Dealer says 50:1 is OK on most (not all) Lawn-Boys.
I chose to go 40:1.
A full synthetic oil might be OK @ 50:1.
I personally am skeptical about high stress engines like
chain saws or weed eaters/edgers.

 

[Cujet]

Originally Posted By: ksJoe
Do you think 50:1 really provides optimal protection, or is that the result of pressure from the EPA?


I have posted on this many times. You could search for some of my posts on 2 stroke oil tests.

32 to 1 is enough to provide adequate lubrication for most low and moderate stress engines. 16 to 1 is required for ultimate wear resistance on high stress engines. However, you are very unlikely to come across a 50cc engine that produces 20HP in your lawn equipment.

 

[beanoil]

Cujet has it. Generally, the more oil you feed your two stroke, the more power you make, and with the least amount of wear, if jetted correctly. It has been proven time and again that high ratios are false economy over the long run. And no, you gents that have successfully run Amsoil at 100:1, or Thisoil at 50:1, or Thatoil at 75:1 are not going to change the data sheets I have from motocross days gone by, or the facts in A. Graham Bell's book, Two Stroke Performance Tuning. Every two stroke at my house gets 32:1.

 

[Quattro Pete]

Quote:
Some recommend using extra oil in the gas during the breakin.

Quote:

I always added a little extra oil to the gas


Quote:
I use 40-1 for the first couple of tank fulls,


According to STIHL:

Quote:
STIHL recommends a mix of 50:1 high-quality (89 octane minimum) regular unleaded gasoline to STIHL engine oil. This same mix ratio should be used during break-in.

 

[IndyIan]

Originally Posted By: Cujet
Originally Posted By: ksJoe
Do you think 50:1 really provides optimal protection, or is that the result of pressure from the EPA?


I have posted on this many times. You could search for some of my posts on 2 stroke oil tests.

32 to 1 is enough to provide adequate lubrication for most low and moderate stress engines. 16 to 1 is required for ultimate wear resistance on high stress engines. However, you are very unlikely to come across a 50cc engine that produces 20HP in your lawn equipment.

Do you have a link for this? Not that I don't believe you but I haven't read anything that says this before.
I do atleast 40:1 always erring on the rich side, just incase something goes wrong with the carburation, etc... I might make that 32:1 now.

I use to have an 84 IT200 that I ran 20:1 Went a few 100 hours without rebuilding it and sold it, so maybe the 20:1 helped it survive. I still have old t shirts with oil splatter on the backs...