gregziemba

I was woundering why my satio 100 muffler is already tarnish. Is this normal? Or is to lean I hope not because its a new engine. ANy help would be great

fancman

My Feedback: (16)

Tarnish is normal. []

warhwk

My Feedback: (3)

Unfortunately, this is normal. The oil in the fuel burns and causes the varnish.

gregziemba

so the tarnish doesent matter. but it just seems wierd to do that on the frist three flights

gregziemba

is there any way i can clean

fadi

my os 46ax didn't tarnish yet two months and still shining!
On the other hand, the os91 surpass, tarnished from the first minute of breakin

it will enventually happen sooner or later.

j.duncker

My Feedback: (2)

4st exhausts run much hotter than 2st ones. The oil burns on and eventually you finish up with a black exhaust.

I would be interested to know of any COLD cleaner that will shift this and not dissolve the ali. [Not crock pot + antifreeze ]

rwright142

Here's a thread where I show my muffler before and after I cleaned it with Dawn Power Dissolver.
http://www.rcuniverse.com/forum/m_5929584/tm.htm

Gringo Flyer

My Feedback: (18)

When you assemble the muffler originally I find if you put some RTV on each end of the elbow the varnish doesnt build up as fast because you are lesss likely to have some leaking through those joints and less fuel gets on the muffler. For the most part though its just part of the program.

gregziemba

so its all right if the gas is black on the plane?

GRANT ED

If the residue coming out the engine is black then you are too lean. It should be a honey colour and yes the tarnish is normal. My OS 91's have been tarnished after their breakin.

Don M.

My Feedback: (5)

You guys must be using castor oil in your fuel. Here's a pic of the muffler on my OS 120. 5 years over 300 flights and NEVER been cleaned. Yes it is still 100% original including bearings.

Villa

Hi gregziemba
The black material that comes out your muffler indicates that aluminum is being ground up. Most often it is that the muffler is not firmly connected. It is best to clean both flanged surfaces, plus the muffler joint (that makes the muffler two pieces) then generously coat it with RTV Automotive Adhesive Sealant. Put some also on both ends of the long thread. Coat the long bolt threads with blue Loctite. I use the fuel with synthetic oil in it because this oil will not burn on to the muffler as easily.

Jackster00

RWright has the right idea here. I've used the Dawn Power Dissolver (cold) direct from the grocery store on all my 4C engine mufflers and it cleans them beautifully. This stuff works well on all engine parts-makes them look new. No work involved. This is good stuff and CHEAP!
(I don't work for Dawn)

Jackster

hebertjj

Don M. is right about syn oil being better than castor for tarnish, but he's obviously cheating on the bragging about his "clean" OS120 muffler. As Duncker noted, the 4C exhaust is hotter, but DonM's extension cools it before it gets to the muffler, thus less tarnish.

Don M.

My Feedback: (5)

I've only been "cheating" for the last 125 flights. The first 200 flights the engine was in a GP Spacewalker and did not have the flex pipe on it. Just in case you don't believe me ..........

hebertjj

Don, I didn't say I didn't believe you; I just said you were cheating on the bragging rights. I also now note that you are one of those Canuck flyers, so there's another way you're cheating; flying in all that cold air up there keeps the tarnish from forming also! It's a well know fact that flying down here in the warmer climes, where real men fly, tarnish build up is a bigger problem.

Hah,
Joel

ArCeeFlyer

My Feedback: (1)

I know there is a big difference between the synthetic oil and castor oil for varnish buildup. Also a higher nitro content will cool the muffler down more. I was running 30% nitro heli fuel (all synth) in my Saito .72 4 stroke and barely had a few spots on the muffler. When I ran out of that I decided to use up my 15% nitro standard fuel with castor/synth mix and after only 3 weekends the muffler is solid black on one side and runs fine, although a big power drop from the 30%.

Don M.

My Feedback: (5)

I'd rather be up here in all this "cold" air than down there with all that "hot" air

Ed Smith

I am not so sure about all "That cold air up there". yesterday was 100F on my patio.

Ed S

da Rock

Don,
Notice that gunk built up around the pressure fitting??? Guess your magic fuel actually had some castor in it if crud on mufflers comes from castor and doesn't come from synthetic only fuel, right?

What you got is a great picture of a muffler that didn't get leakage anywhere but around the pressure fitting and darned if that didn't burn on pretty good..... or pretty bad.

Don M.

My Feedback: (5)

No where in my posts did I say that there is NO tarnish on my muffler. Since you are so good with the arrows point that part out to me. Besides I have more to do with my time then argue with someone who just has to be right at all costs.

Ed Smith

Without entering into the "Picturers with arrows" discussion I will add this. It is a simple well known fact that the more castor oil in the fuel, the more tarnish on the outside of the engine and the more varnish and gum inside the engine.

Ed S

Don M.

My Feedback: (5)

And that was all I was trying to say in the first place .........

Amen ................

saintcreed

My Feedback: (205)

Some of the above post are very good as to what causes the tarnish and how to stop the majority of it....You guys have to remember the exhaust threads on all engines are what we call straight threads....not tappered...a straight thread will leak no matter how tight you think you have it....that is the reason some have suggested the high temp silicone sealant...the red tube at any auto parts store....a good way to install it is put a ring of sealant around the threads on the exhaust pipe...now tighten until you see the sealant start to ooze out...just before it starts to tighten...at that point stop let it set overnight...the sealant will set up and when tighten now will form a gasket....do the same on the pressure fitting....whaaalllaaa...no leak no more....now to clean...haven't tried the method mentioned above, but one I've used for years is the anti freeze in a crock pot...and not the one your wife or mother cooks in...anti freeze is a poison..no matter how much you wash it there will be residue left, get one a a yard sale for $5 or so...put in enough anti freeze to cover the parts...let it set for 4 hours or (sometimes more time will be needed if the item is really bad...)so on high...remove the parts....mufflers, 2 stroke heads, and this will even loosen up an engine that is seize up, from fuel residue after setting around...on the parts being remove, use a pair of pliers and a rag...things coming out of the crock are going to be HOT!...use a tooth brush or such, brush off any residue that's left...now take some 4/0 steel wool (nothing heavier)...hold it in the palm of your hand and take the muffler,,,after it's cooled...in the other hand and rotate in around the muffler....do not go length wise...for the preceeding part I have a long 6" 3/16" bolt I put through the muffler then install a nut an washer, tighten down real good...with the excess length of bolt sticking out install in a battery drill...again hold the steel wool, 4/0, in one hand and turn the drill on...a varible speed drill here is a nice option...again walla...shinny again...now do you want it shinner...now there is a word...get some brasso cleaner at the hard ware store..again while still attached to the drill, apply like one would when polishing your car... you will be amazed at the black residue that comes off...this will take a couple rags or so....but what a shine....One can also do the 4/0 steel wool, brasso polish, 3/16 bolt trick on your true turn spinners...one can almost see ones reflection in it when done....try it you'll be amazed at the results...