WeatherB

iTrader: (4)

Hey guys,
I purchased a new RD Logic engine and the piston and sleeve are very tight when turning by hand.

I added some after run oil to the engine before turning it over by hand for the first time; however, it is still very tight.

I don't think my starter box would be able to turn this engine over, but I haven't tried it yet.

Any suggestions on getting this thing going?

cdelong

iTrader: (12)

heat the case with a hair dryer and loosen the glow plug a little. when it starts, snug the glow plug back up.

don't forget to place the piston at the bottom of it's travel after running it.

kyoshoBOY

Tried turning the flywheel by regular screwdriver and whe n the piston is loose and in the bottom,put a little fuel on carb and then tried start it again,and if it stock again n the top do the same thing again.
You need to break in the motor at least 15 tanks at 170f maximum temp.let it coll down everytime you finish 1 tank and don't forget to put the piston on the bottom everytime the engines turns off.
Hope this help.

WeatherB

iTrader: (4)

Thanks, got it.

Seems to turn over just fine when using the starter box.

sedanaddict

everybody has a different opinion about break in but i disagree with kyoshoboy in that 170 degrees is not hot enough to "seat" the parts and an overly cold break in does more damage than a hot one. i get my motors up to 210-220 at least during the first 10 tanks and let them cool between each tank. never rev the engine past 1/4 throttle until 8 or more tanks and let it just idle for the first two or three tanks. like i said you will hear different things from different people.

onnetz

here is how much aluminum expands under heat..

12 x 10^-6 per 1o F this comes out to about .000012"

it depends on the engines tolerances as to how much heat is needed for break in..

and steel expands 1/2 as much as aluminum under heat..

WeatherB

iTrader: (4)

You're right, everyone says different things.

I heard 180°F for first or second tank and then 200 - 220 from then on.

kyoshoBOY

Yap you will heard a lot of diff kind of ideas and opinion from other racers on how to break in an engine.
This is what I do to break in my engine(this is my own way)
1. Put 3 drops of after run oil on the top of piston.
2. Rich the top needle by half turn from the factory settings.
3. Start the motor and run it idle for 2 tanks and then after that 2 tanks,run it to the track,and half or quarter throttle on the turns and full throttle on half of straight away and gas it again for the remaining half,stay on 170 to 180f.
4. After each tank put the piston BDC after run,and let it cool down till it drop to 60f or 70f.
5. You'll feel the motor if it breaks in when the motor richin up,then your almost there.

This is my way,and it works great for me.

cdelong

iTrader: (12)

I break in a lot of engines and notice the piston does not stop sticking at TDC while starting until I cycle the engine around 220F a few times. It may only take 3- 4 tanks till I'll run it hard, but that equals about 1- 1.5 hrs running time. I can get 5- 6 five minute cycles on a 125cc tank.

When the engine will start without heating it prior to bumping it over, and does not stick at TDC, I run 1 more tank through it and let it rip after that.