Engine residue

What color should engine residue be? I ask because my engine is depositing a grey, metallic substance on the wing of my Twist 3-D. I don't think this should be the normal color. I'm using Omega 10% fuel (pink in color). Is this normal break in residue or not?

On another note, my K&B Sportster quit today right before lift off. I just had enough runway left to land, but it made sort of a bang prior to shutting off. Now, it appears as though there is no compression like before. The plug is still good, and the piston still moves up and down...any ideas?

Thanks

Reply to
Darren Earle
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Engine residue from a two-stroke, such as a Sportster should be almost clear... a silver-gray metallic look to the exhaust residue is almost always due to a loose muffler, or loose muffler parts... A thick black residue is indicative of the engine trying to eat itself...

You may have a damaged piston/liner based on the "no compression" comment, and the piston could be chewed up.....

Good luck,

Bill

Reply to
Bill Fulmer

Same engine? Sounds like you lost the piston, liner or, most likely, both. That metallic substance is probably metal being abraded from inside the engine for some reason.

Reply to
Fubar of The HillPeople

ANY metallic residue in the exhaust is BAD! That means there's aluminum being eaten somewhere. If it's blackish, the engine is probably too lean. A greyish color may mean the muffler is loose, or it may also mean the engine is too lean.

Use a castor/synthetic oil mix (Omega) for ABC/ABN engines, and a pure castor (Cool Power) for all else.

Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver

Cool Power is 100% SYNTHETIC oil Morgen does't make a 100% Castor fuel

Reply to
O4U2P

I never like to disagree but Coolpower is not necessarily 100% Synthetic. refer to =

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supplies several types of oil including CleanCastorT and their Omega oil is 20% Castor and 80% Synthetic. AVAILABLE BLENDS FAI - 17% (30% Castor 70% High Viscosity Lube) 40% - 17% (30% Castor 70% High Viscosity Lube)

5% - 17% (30% Castor 70% High Viscosity Lube) 15% HELICOPTER - 17% (30% Castor 70% High Viscosity Lube) 10% - 17% (30% Castor 70% High Viscosity Lube) Large Super T - 12% (30% Castor 70% High Viscosity Lube) 15% - 17% (30% Castor 70% High Viscosity Lube) 4 - CYCLE 17% (50% Castor 50% High Viscosity Lube) 25% - 17% (30% Castor 70% High Viscosity Lube) JET 7% - 20% (30% Castor 70% High Viscosity Lube)

regards Alan T. PS: Please check my web site for much more information under "Fuel" Alan's Hobby, Model & RC Web Links

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Reply to
A.T.

If the residue problem is coming from the same engine that went "bang" prior to landing, your troubles may be over and the original question may be a moot point. From my experience, a sound similar to a "bang" coming from an engine means I get to go shopping :-)

MJC

Reply to
MJC

Alan The information you posted was for Morgan's Omega brand fuel.

If you will check DR1's and my original post you will see that the fuel in question was Morgan's Coolpower brand.

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you will find that my post was correct when I corrected DR 1 when he wrote that Coolpower was 100% castor.

Morgan does't make a fuel with 100% Castor

I do like your web site and use it often

Terry

Reply to
O4U2P

And you're absolutely right. All I can plead is massive brain fart! Thanks for the correction!

My wife says it's a "senior" moment, but I'm NOT that old! :)

Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver
"

my K&B Sportster quit today right before lift off. I just

cylinder liner, but runs the piston directly in the silicon treated cylinder bore. from what i can remember reading the early sporsters ran too cool and leaked compression at the head and base of cylinder at the block if the four holddown screws were not tight.later engines were made with reduced fins so the engine would get up to proper run temp. i have two .65's, .45 and a .20(25?i gave away) and all ran good. the "bang" you heard may be from leaking cyl. head and back fire, then no compression, or blown hole in the top of the piston ,if ya can see piston still moves (rather than thrown rod)..you may try checking seal at the head & block, i don't remember sportsters useing a head gasket. good luck, hjh

Reply to
john hebert

Hey if you are old enough to have a wife your can have a senior moment. Remember, getting married is the first evidence that a man has lost his mind which is the first stage of 'senior moments'. Or have you NEVER forgotten something important to her?

Reply to
Six_O'Clock_High

I'm still alive, aren't I? Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver

THAT only speaks to HER compassion.

Reply to
Six_O'Clock_High

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