Gas engine break-in procedure...

[Mark Davis]

There is some controversy on the SOP for proper gas engine break-in procedures... I've started this thread to have the FG membership share their methods of breaking in a gas engine for our application...

Not being one to "read between the lines", I normally adhere to manufacturers recommendations for breaking in an engine... Which is to set the high & low needles to factory recommended settings and to run the recommended oil at the suggested ratio... I've been breaking in gas engines with LawnBoy at 32:1 for years... No problems, no stuck rings, no excess carbon buildup on the pistons, no dead-sticks, no burned up engines... I usually run 2 gallons through a single cylinder engine and 4 - 6 gallons through a twin in this manner... As the engine breaks in, I will lean the bottom end from factory settings until it doesn't 4-stroke... In no way will I tune an engine for optimum performance until I have finished the break-in process... This is where the disagreement begins... It appears that a few FG members disagree with the method, as I have been taken to task over my methods... Sorry, but I've seen too many people lean their engines too early, trying to get optimum performance only the have dead sticks and losing airplanes... Once I have finished the break-in process, I tune the engine for optimum performance based on altitude, temperature and atmospheric conditions... Sounds perfectly logical to me, but obviously I'm missing something as there are a few members pissing on my shoes for my technique...

Be advised that some manufacturers are now shipping instructions with their engines for the user to NOT touch the needles... Brillelli is the one that comes to mind...

Let's hear what the consensus is on the topic...

[zzw26n]

You don't have enough options to select from for an appropiate answer.

The Engine should be mounted to your Plane, assembled and started using the recommended break-in oil and mixture. Servo settings adjusted for end points. Then the L & H end needles should be adjusted for your environment, air, altitude, etc.
The Engine should run fine at Full Throttle, Transition should be good and have an idle you can trust. Then Fly it for the recommended break-in time (3-4 gallons) using the recommended break-in oil (Lawnboy 32/1)

I have 8 DA Engines, only had two run at factory settings, but all of them were adjusted by the above methods. And I've had burbling on some, but never a dead stick or flame-out.

just my .02 cents

[3ddd]

that's all fine and dandy but myself i find that alot of people think a gasser needs to be sloppy rich like a glow engine.that is not the case,use the recommended oil mix and set the needles 3 to 400 rpm under max rpm on the high side and set the lowend for good transition with just a hint of burble in the 1/4 to 1/3rd throttle position.after the break in period you will lean the oil somewhat and retune slightly and will not have any problems.i have run some of mine as long as two years and never touch the needles,and you can be assured that if it was not running right i would be the first to retune it.just my 2 cents,hope this helps as for oil i like a good dino like golden spectrum at 32:1 for a gallon or two then i go for syn at about 50 :1 for a gallon or two then myself i run amsoil sabre at 100:1 and have never had a problem.works for me is all i know.no deadsticks in over three years

[Jcarte]

I like to break mine in at full throttle for at least 5 minutes, usally the jugs are hot enough to seat the rings. I also mix a little sand in with my first tank, it helps scatch the cylinder walls just enough so I get more lubricant on the piston which inables me to run the engine leaner inturn giving me more RPMs and power. None of the manufactures agree with my process, nor did they like it when I told them that my engines run better if I use butter milk for after run oil.

[3ddd]

real good,what if some noob thinks your for real and tries this?

[prizzy]

I think that you need to tune them a little if it is really 4 strokin, and really burbling. You just want a little of both so you know you are getting enough fuel. I am insterested in seeing what everyone else says. Good thread.

[prizzy]

Jeff, you are letting out all your secrets. I never thought you would reveal the buttermilk trick??

[Jcarte]

If some noob is that gullable then he shouldn't be flying giant scale

[3ddd]

yea but you know how that goes lol

[flyin woodbutcher]

	Quote: Originally Posted by Jcarte
	If some noob is that gullable then he shouldn't be flying giant scale

Why do you have to go and call me a noob now. I followed all your written recomendation's. Does this mean I have to give up the steering wheel to my Carden Edge 540 FD ?

FWB


PS the buttermilk is bad ass.

[Surly_Schmidt]

Tune it right and do 10 x 5min runs with lots of high throttle and small prop.. That way it wont get hot, heat is the real killer. A little tweak of the needle is not going to affect the oil content in the motor that much. Thats the way I do it.

[rede2fly]

you mean i cant use virgin olive oil anymore?? hey instructions are for people who dont know what they are doing

[flyin woodbutcher]

	Quote: Originally Posted by rede2fly
	you mean i cant use virgin olive oil anymore??

more fun to just wipe some olive oil on a Virgin anyhow.

[Bill_Higgins]

The proper break-in procedures, are whatever your manufacturer recommends !

Bill

[Surly_Schmidt]

I never understood others infatuation with virgins