My brother noticed, after running his Rustler today, that the bottom of the glow plug, like around the coil was a dark brown color. Also the top of the piston was brown. Any Ideas of whats happening.. hes running sidewinder 20% w/12% oil... thanks for any help

its not unusual for the piston to be a little discolored once you get some good run time on it. its probably just a little carbon build up, completely natural. also, the best place for questions like this would probably be the car engine forum, there are a lot of good guys there to help you.

If the top of piston and the glow plug are a dark brown that is an indication that you are running the engine too lean. Richen it up a bit if, your engine is tuned right the top of the piston and the glow plug should have a slight tint of brown tho both of them. But it should never be a dark brown. Richen up the high end and low end needle's a 1/4 turn at a time until u see a good stream of blue exaust coming out the stinger at all times.. But all in all you ran the engine to lean.

alright guys thanks for the info...

looks like weve got two conflicting ideas. do you have any pics of the top of the piston? hopefully its a light brown.

A light brown on the top of the piston and on the glow plug is ok but the way he's making it sound as if it looks really dark brown and a really dark brown piston and glow plug is bad. I do agree with WIDE OPEN, some discolerisation (sorry if it's spelled wrong) on the piston and glow plug is ok.

can i start the car without a glow start it has a pull start and a glow plug what dose that meen im new at this

with a pull start you must have a glow plug heater, if not, you will get no ignition at all, and will pull and pull and pull to no avail.

YIKS........ DUDE [X(] AND HOLY CRAP !!! Yor lucky it's not black. The nitro amount is fine but if you are running the stock motor (TRX 2.5) you are starving it for oil that motor NEEDS at the least 18% oil .

toxic 2u i dont think any of these engines need 18% oil content in the fuel that is way to high of a oil content. All he needs to do is richen it up a little if it's a dark brown. but having a oil content of 12% or higher in these motors will hurt it more then it will help 8% to 12% oil is fine but not 18%.

From my experience a brown colour is just oil.(I use fuel with castor oil, not many car fuels use castor) The more brown present the more oil the engine has while running. This indicates a rich setting. If the glow plug element is a distinct white colour, this indicates a lean setting.

A lean setting would burn this brown oil off leaving more metal visible.


Ryan

[>:]
You don't know what your flappin yer jaw about. Have you ever read on a can or bottle of Traxxas top fuel how much oil is in it ? NO?
traxxas recommends useing top fule cuz the TRX 2.5 runs such high RPM's and naturally runs hot . Look and see for your self [sm=punching.gif]

Toxic 2u No i have never read the bottle of traxxas fuel cause i dont use it and there's a reason y i dont. He's using sidewinder fuel and the fuel that he's running is fine. I ran my traxxas engine with racing fuel that has 8% oil content in it and it has more then 8 gallons through it now. And by the way i do know what im talking about i have been in this hobby for a little while now Im not saying that u dont have more time then me in this hobby. He never said he was running a trx engine so all we know he's running another engine in his rusty. We just simply dont know.

I use fuel with 20% oil content and have no problems. The reason I use a fuel with high oil content is it's also used for my boats. I am just starting my fifth gallon of fuel.

Most, if not all car/buggy engines will be fine using 8-12% oil.

Ryan

For one thing i never said 20% oil content will not work i just said that 20% is not needed for these engines. A lot of people including me will say if uyou run more then 20% oil content in the engine will actually hurt it. Thats just our opinions, everyone has there own opinions and for ryan t888 i undesrtand what your saying and thats fine. But i have never ran traxxas fuel and more then likely never will. Had some friends that ran it and had bad experiences. Thats y i run other fuel. But you do not need 20% oil content for the traxxas engine. As I said earlier with my experinece with my motor.

a picture would be great right now so you people can stop arguing about your freaken oil percentage.

Is there any place that has pics of pistons run in various conditions to illustrate what it's signs are?
Like in my 'Haynes' manuals that I get for every car I buy, there is a full color page with nothing but spark plugs that have been killed under different conditions, so you can read your plugs and see how your engine is running.
I think that would be a very useful tool, if anybody knows where to find it.

Traxxas top fuel bad[:'(] (doesn't this have like 5% oil)
Trinty Platnum bad [:'(] (the pro guys use this b/c they get all the motors they need)

Fuel w/15-20% oil good(motor will last as long as you have the truck)

Especially when breaking in a motor you should use at least 15% 20% would be my recomendation.

avgwhboy if tou would read the post up further we have come to the conclusion that the traxxas fuel has 20% oil content in it. For the trinity platnum i have run trinity platnum for a while now and have had no problem with it at all. Have recently bought o'donell fuel just to see how it runs. O'donell is cheaper right now at the LHS. Anf as for unclezesta if you dont like our discussion you can always stop reading it and go back. Thats all i got to say about that. But i will never run a fuel with over over 20% oil content in it I just think that is way to high of a oil content

Okay i want to step in here. i have a guy who has been in this for a while who custom blends my fuel. My mix is 25% nitro and 3% benol and 5% Klotz. so just 8 % .
i used to use 18% oil hobby shop fuel, it is too much for me, it makes little horsepower and revs slowly and it is also hard to get it nice and lean because it has so damn much oil, i lean my engine until it stalls under acceleration then back it off 1/4 of a turn. dont worry about this method hurting the engine because it will cut out as soon as its too lean (equivalent to running the tank dry) and another 1/4 turn richer gives PLENTY of margin for error (ie will not starve for fuel).

with 18 % oil it is very hard to get this right. and as with traxxas fuel, my mate runs normal 18% oil store bought fuel and it runs sweet as, even on my 8% oil blend it runs cool.
i have a crazy idea, maybe traxxas say that so you spend more money with them...?
If you rad the OS engine manual it says a recommended 12% oil and the novas are usually 10%, i run even lower mainly for performance, like white lightening its low but definately enough. especially seeing as how its angus nitro and benol and klotz.

Dann