Engine residue

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

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.

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!"

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

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

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

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

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.

Morgan does't make a fuel with 100% Castor

I do like your web site and use it often

Terry

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!"

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

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?

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

THAT only speaks to HER compassion.