Nickybuggy
RCTalk Member
Just wanted to know if this is an idication that I'm running the engine too lean or too hard because there is enough smoke to indicate a slightly more rich than normal tune (20% nitro, 15% oil, medium plug)
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Colour of piston head yellowing
- Thread starter Nickybuggy
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What color is the fuel? What's the engine temps you're running?
Are you talking about the actual surface of the piston itself or the external crank case near where the piston is?
The engine internals tend to tarnish a bit due to the castor oil in our fuel. If you have pitting on the surface of the piston, then you have issues.
The engine internals tend to tarnish a bit due to the castor oil in our fuel. If you have pitting on the surface of the piston, then you have issues.
well i have only been in nitro only 2 1/2 years, but i think the color is ok. you DONT want the piston covered in black, back in the 60s running nitro hemis it was called black death, lack oil AND to hot caused this.
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I don't remember which fuel left the yellow. Byron's or O'donnells, maybe? This is a piston in an engine running Blue Thunder. It's a sign of a good tune. You don't want to see brown or black or a dry piston top.
Nickybuggy
RCTalk Member
- Thread starter
- #6
I'm running AT Racing fuel which is pink in colour I have no idea what the exact temp is but I'm pretty sure it's not too hot and I've run about 2L of fuel through it
And I mean the piston head itself
---------- Post added at 2:20 AM ---------- Previous post was at 1:51 AM ----------
And I mean the piston head itself
---------- Post added at 2:20 AM ---------- Previous post was at 1:51 AM ----------
Zebadee
RCTalk Basher
A yellowish tinge is not bad. I run pyromaster 20%, and the top of my piston is amber colored.
It's oil varnish, and completely normal.
It's oil varnish, and completely normal.
Here's a few of mine to compare:
Middle one was a buddy of mines, this was a photo I took before sending them in for a pinch service. One on the left had roughly 5 gallons through it, one in the right had many more, one in the middle probably had 5 or 6 through it. It was run pretty rich and pretty hot, hence the black coating. This was my friends first nitro RC. He takes much better care of things now.
A little discoloration is normal. If it's black, your running it hard and rich. Maybe too high geared in the wrong terrain or something. The yellow tinge is normal though.
Middle one was a buddy of mines, this was a photo I took before sending them in for a pinch service. One on the left had roughly 5 gallons through it, one in the right had many more, one in the middle probably had 5 or 6 through it. It was run pretty rich and pretty hot, hence the black coating. This was my friends first nitro RC. He takes much better care of things now.
A little discoloration is normal. If it's black, your running it hard and rich. Maybe too high geared in the wrong terrain or something. The yellow tinge is normal though.
Zebadee
RCTalk Basher
Running it rich don't damage things like running lean will 
Rich = Safe almost always.
Rich = Safe almost always.
Too rich can damage it by not clearing the fuel/air out of the cylinder and hydrolocking it. Also may keep it running too cool causing it to wear down the piston/liner faster than it should.
That said, I run mine a bit on the rich side. Not so much that I have to fight with it to keep it running, but enough to where if I let it sit and idle for more than 10 seconds, I usually get a gurgle or two as it clears it's through when I gas it.
That said, I run mine a bit on the rich side. Not so much that I have to fight with it to keep it running, but enough to where if I let it sit and idle for more than 10 seconds, I usually get a gurgle or two as it clears it's through when I gas it.
Nickybuggy
RCTalk Member
- Thread starter
- #11
Yeah mine does the same I've compared my tune with others running the same engine and fuel and it's close to exactly the same as theirs so with all of this evidence I'm pretty sure it will be fine because my last engine had a black piston head and it shattered from the inside so I know the limit of the engine and how hard to run it.
Thanks guys
Thanks guys