whaturi

on my new 58, i bought it without the included oil, so i am using motul 800 to break it in. the only thing is how much should i use before it's broken in? also, am i to keep the stock settings on my carb for the whole break in? they are very rich, but i will if i have. we did lean the low end a little as it was just to rich to fly like it was.

DarZeelon

Vincent,


You can use any synthetic oil, for break-in, that meets, or exceeds the JASO-FC standard.

I suggest 25:1 ratio for break-in and going to 33:1 for general use.

Using 40:1 is the oil ratio in the instructions that come with the engine.


Please read the carburettor adjustment instructions and act accordingly.
Gas engines don't need as rich a mixture like glow engines, for break-in.

pe reivers

Ditto. One gallon of 25:1 should complete the primary break in period and to finally set the needles and get her ready to fly.
If the engine is Way too rich, lean out to slightly rich. Keep engine loads down fpr the first gallon, and slowly in short bursts increase loads. Go slowly here.
You might want to check the procedures for the UL Rotax engines http://www.800-airwolf.com/ tech info

whaturi

i mixed it up 30 to 1. i guess i can add in a bit more oil to this gallon. i haven't flown more than 1\4 gallon yet. so after that first gallon, i can lean both needles to where they should be? we did have it lean the first day and it had a lot more power than now, because i went back to basic settings.

pe reivers

the richer (not slobbering rich) setting does two things. It keeps the temperatures down, and it provides more oil to flush wear particles out of the engine. The latter also can be achieved with more oil in the mix. If the mixture is set too rich, the cure is worse than the ailment, because it tends to foul the engine inside, especially the plug, which needs a minimum heat to burn itself clean.

The other day I used a tach and Infrared gun to set a 35cc engine with lacking power. IR measurements of the head showed a low 95 degree (C) so I leaned the needle. As temperature was raised to the 140 degree mark, so did rpm rise. I left it there, knowing that the engine was still rich. A well leaned out engine runs between 150 and 220 degrees upper cylinder/head temperature, but some reserve must be kept because of the inaccuracy of IR measurements.

whaturi

so i would be well off to add a bit more oil to the mix and just get the needles where they need to be? this thing runs so well already, i am sure it is going to be a strong one. do i risk actually ruining the engine at this point or are these breakin things just that last "little bit " one can do to prolong engine life? i do not have a temp gun. i am for sure rich, because the first day i ran it, i had it leaner on both needles. now i have it more rich and i can tell because my uplines are slower, and the low end burbles just a bit.

what happens to gas engines that are just tuned right away with no breakin period? i am not really sure what to do, since i already mixed up my gas at 30 to 1. it seems there are many ways to do this..

pe reivers

What is the colour of the central spark plug electrode?

whaturi

dark grey.

whaturi

why are you using 25 to 1 if the manual suggests 30 to 1? will i be ok if i just continue with 30 to 1 and keep it on the rich side for the first gallon? this engine runs very well. and very powerful on my 18 pound plane! im hooked on gas.

pe reivers

the more oil in the mix, the faster the oil in the engine circulates. In a new engine that is important.
Experiments of Gordon Blair showed that it took 1/2 hour for all the oil in the engine to be replenished. At a 5% oil mix! That is one of the reasons why I believe in "more oil is better"

Dark grey is good for running in. As the engine loosens up, this can be changed to light grey by tweaking the H-needle.

whaturi

thank you very much.

pe reivers

Yuo'r welcome

whaturi

i ran it again yesterday and leaned both needles out some. we got it to 6000 rpm max. the only thing was, even with over a quarter turn on the high end needle, i could not get the rpms to drop any lower than 5950. i ran it like that for 5 flights and it ran great. didn't seem hot either. i am using an NX 24-10 and a pitts muffler. not sure of the make.

how many more rpms can i expect to gain after 10 gallons?

pe reivers

You will see no, or hardly any gain, unless you very-very carefull train the engine to work. That is due to the MVVS graphite piston coating which delivers power from day one. The engine settles in it's best power rythm after about two pints of fuel. It is by no means run in yet at that time. Leaning to the limit too soon will damage your engine to the extent, that it will never get very smooth.
Watch that central electrode color. It should not be white (lean) or purple (pre-ignition)

whaturi

thanks again, you have great info!